...
- Events that are written by ONAP components.
- Propagation of transaction and invocation information between components.
- MDCs, Markers and other information that should be attached to log messages.
- MDC = Mapped Diagnostic Context
- Human - and machine-readable output format(s).
- Files, locations and other conventions.
Java and Python are supported, but conventions may be implemented by other technologies like GO.
Original AT&T ONAP Logging guidelines (pre amsterdam release) - for historical reference only: https://wiki.onap.org/download/attachments/1015849/ONAP%20application%20logging%20guidelines.pdf?api=v2
The Acumos logging specification follows this document at https://wiki.acumos.org/display/OAM/Log+Standards
Logback reference: Logging Developer Guide#Logback.xml based on https://gerrit.onap.org/r/#/c/62405
Introduction
The purpose of ONAP logging is to capture information needed to operate, troubleshoot and report on the performance of the ONAP platform and its constituent components. Log records may be viewed and consumed directly by users and systems, indexed and loaded into a datastore, and used to compute metrics and generate reports.
...
This document proposes conventions you can follow to generate conformant, indexable logging output from your component.
How to Log
ONAP prescribes conventions. The use of certain APIs and providers is recommended, but they are not mandatory. Most components log via EELF or SLF4J to a provider like Logback or Log4j.
EELF
EELF is the Event and Error Logging Framework, described at https://github.com/att/EELF.
EELF abstracts your choice of logging provider, and decorates the familiar Logger contracts with features like:
- Localization.
- Error codes.
- Generated wiki documentation.
- Separate audit, metric, security and debug logs.
EELF is a facade, so logging output is configured in two ways:
- By selection of a logging provider such as Logback or Log4j, typically via the classpath.
- By way of a provider configuration document, typically logback.xml or log4j.xml. See Providers.
SLF4J
SLF4J is a logging facade, and a humble masterpiece. It combines what's common to all major, modern Java logging providers into a single interface. This decouples the caller from the provider, and encourages the use of what's universal, familiar and proven.
EELF also logs via SLF4J's abstractions as the default provider.
Providers
Logging providers are normally enabled by their presence in the classpath. This means the decision may have been made for you, in some cases implicitly by dependencies. If you have a strong preference then you can change providers, but since the implementation is typically abstracted behind EELF or SLF4J, it may not be worth the effort.
Logback
Logback is the most commonly used provider. It is generally configured by an XML document named logback.xml. See Configuration.
Log4j 2.X
Log4j 2.X is somewhat less common than Logback, but equivalent. It is generally configured by an XML document named log4j.xml. See Configuration.
Log4j 1.X
Strongly discouraged from Beijing onwards, since 1.X is EOL, and since it does not support escaping, so its output may not be machine-readable. See https://logging.apache.org/log4j/1.2/.
This affects OpenDaylight-based components like SDNC and APPC, since ODL releases prior to Carbon bundled Log4j 1.X, and make it difficult to replace. The Common Controller SDK Project project targets ODL Carbon, so remaining instances of Log4j 1.X should disappear by the time of the Casablanca release.
What to Log
The purpose of logging is to capture diagnostic information.
An important aspect of this is analytics, which requires tracing of requests between components. In a large, distributed and scalable system such as ONAP this is critical to understanding behavior and performance.
Messages, Levels, Components and Categories
It isn't the aim of this document to reiterate the basics, so advice here is general:
- Use a logger. Consider using EELF.
- Write log messages in English.
- Write meaningful messages. Consider what will be useful to consumers of logger output.
- Use errorcodes to characterise exceptions.
- Log at the appropriate level. Be aware of the volume of logs that will be produced.
- Log in a machine-readable format. See Conventions.
- Log for analytics as well as troubleshooting.
Others have written extensively on this:
- http://www.masterzen.fr/2013/01/13/the-10-commandments-of-logging/
- https://www.loggly.com/blog/how-to-write-effective-logs-for-remote-logging/
- And so on.
Context
MDCs
A Mapped Diagnostic Context (MDC) allows an arbitrary string-valued attribute to be attached to a Java thread via a ThreadLocal variable. The MDC's value is then emitted with each message logged by that thread. The set of MDCs associated with a log message is serialized as unordered name-value pairs (see Text Output).
A good discussion of MDCs can be found at https://logback.qos.ch/manual/mdc.html.
Example
From Lukes call graph work
Code Block | ||
---|---|---|
| ||
LogEntry(markers=ENTRY, logger=ComponentAlpha, requestID=eb3e0dc2-6c3c-4bb7-8ed6-e5cc4ec7aad2, invocationID=06c815ef-5969-45cc-b319-d0dbcde89329, timestamp=Tue May 08 04:23:27 AEST 2018) |
Mapped Diagnostic Context Table
- Must be set as early in invocation as possible.
- Must be unset on exit.
TODO 20180607: USE case and Code mapping for each required MDC below
...
Associated with
markers
Required
Y/N/C (C= context dependent)
N = not required
...
EELF Metric
...
EELF Debug
...
RequestID
...
See above.
UUID only
...
See above.
UUID only
...
If known, this field contains a universally unique identifier used to differentiate between multiple instances of the same (named) log writing service/application. Its value is set at instance creation time (and read by it, e.g., at start/initialization time from the environment). This value should be picked up by the component instance from its configuration file and subsequently used to enable differentiation of log records created by multiple, locally load balanced ONAP component or subcomponent instances that are otherwise identically configured.
Handles parallel threads or running across a load balanced set of microservices - for identification
...
See above.
The service inside the partner doing the call - includes API name
...
See above.
MDC-PartnerName (the larger component doing the call)
for example SDC-BE instead of just SDC for the overall pods
...
This field indicates the high level status of the request. It must have the value COMPLETE when the request is successful and ERROR when there is a failure.
Discussion: status/response/severity relationship
status = global, response below is app specific
Ability to render severity-like line in a non-debug log
...
Y-20180412
*Note: 1
...
Y-20180412
*Note: 1
...
OPS specific
Use/Map existing? https://www.slf4j.org/api/org/apache/commons/logging/Log.html
ENUM is INFO/TRACE/DEBUG/WARN/ERROR/FATAL
By default - align this severity with the reported log level
(optionally a way to map actual level from reported level if required)
...
This field contains the Virtual Machine (VM) Fully Qualified Domain Name (FQDN) if the server is virtualized. Otherwise, it contains the host name of the logging component.
Best effort (ip, fqdn)
(previously covered by removed "Server" field)
redundancy between clientIP, server, virtualServer name is OK - and helpfull for runtime OPS/Hybrid envs
superceedes virtualServerName
Report what is in the http header
Discussion: roll all 3 fqdn, hostname or ip into one field - do we ever need two of the 3 fields concurrently?
TODO: Verify what is also available from a filebeat agent when it exists
...
Y-20180412/20180419
...
This field contains the requesting remote client application’s IP address if known. Otherwise this field can be empty.
We don't differentiate between inside/outside ONAP for the IP - this supports hybrid environments
Derived from the system
redundancy between clientIP, server, virtualServer name is OK - and helpfull for runtime OPS/Hybrid envs
Discussion: do we need both ip and fqdn fields?
Report what is in the http header
...
Y-20180412
Ask question of OPS to remove this field - 20180419
...
EntryTimestamp
(previously BeginTimestamp)
Date-time that processing activities being logged begins. The value should be represented in UTC and formatted per ISO 8601, such as “2015-06-03T13:21:58+00:00”. The time should be shown with the maximum resolution available to the logging component (e.g., milliseconds, microseconds) by including the appropriate number of decimal digits. For example, when millisecond precision is available, the date-time value would be presented as, as “2015-06-03T13:21:58.340+00:00”.
Context dependent on whether part of an ENTRY marker
(May 7 comment - as a result of coding - this attribute a duplicate of InvokeTimestamp - delete one of them)
...
InvokeTimestamp
(prevously
EndTimestamp)
...
Timestamp on invocation start
Context dependent on whether part of an INVOKE marker
(May 7 comment - as a result of coding - this attribute a duplicate of EntryTimestamp - delete one of them)
...
It contains the name of the ONAP component or sub-component, or external entity, at which the operation activities captured in this metrics log record is invoked.
Example: SDC-BE
(May 7 comment - as a result of coding - this attribute is derivable)
...
It contains the name of the API or operation activities invoked (name on the remote/target application) at the TargetEntity.
Example: Class name of rest endpoint
Discussion: on building call graph vs human readable single line - keep for human readable
Used as valuable URI - to annnote invoke marker
Review in terms of Marker-INVOKE - possiblly add INVOKE-return - to filter reporting
TBD: Coverage by log file type (debug, trace, ...)
TBD: cover off discussion on reducing log files to two (DEBUG/rest) for C* release
(May 7 comment - as a result of coding - this attribute is derivable)
...
Supported Languages
Java (including Scala and Clojure - because they compile to the same bytecode) and Python are supported, but conventions may be implemented by other technologies like GO.
Java
The library and aop wrapper are written in Java and will work for Clojure (thanks to a discussion with Shwetank Dave that reminded me of languages that compile to bytecode) and Scala as well. see: https://git.onap.org/logging-analytics/tree/reference
Clojure
See the java libraries
Scala
see the java libraries
Python
How to Log
ONAP prescribes conventions. The use of certain APIs and providers is recommended, but they are not mandatory. Most components log via EELF or SLF4J to a provider like Logback or Log4j.
Logging Specification Compliance
For the casablanca release the logging specification has been updated and finalized as of June 2018. Implementation of this specification is required but the method of implementation is optional based on each team's level of possible engagement.
High Level the changes are introduction of MDC's (key/value pairs like requestID=...) and Markers (labels like ENTRY/EXIT)
The ELK stack (indexes and dashboards) is focused on the new specification in Casablanca - if time permits we will have a migration path and/or support for both the older Amsterdam/Beijing release and Casablanca -
Jira | ||||||
---|---|---|---|---|---|---|
|
Level 0: Log specification unchanged
Just keep your code as-is and commit to migrating to the the MDC and Marker focused specification for Dublin - logs will be the older format for now
Level 1: Log specification compliance via local project changes, library or wrapper
Continue to use your own library/wrapper if you have one like in SDC and AAI, change individual source files.
Level 2: Log specification compliance via SLF4J supplied logging-analytics library
Use Luke's SLF4J library directly as wrapper for MDCs and Markers by calling the library from within each function.
Level 3: Log specification compliance via AOP library over SLF4J supplied logging-analytics library
Use a spring based Aspect library that emits Markers automatically around function calls and retrofit your code to log via Luke's SLF4J for internal log messages.
Logging Library Location and Use
see https://git.onap.org/logging-analytics/tree/reference/logging-slf4j
and usage ONAP Development#DeveloperUseoftheLoggingLibrary ONAP Development#KubernetesDevOps and Logging User Guide#LoggingDevOps
see Spring AOP example (minimal changes to existing code base) WIP in
Jira | ||||||
---|---|---|---|---|---|---|
|
EELF
EELF is the Event and Error Logging Framework, described at https://github.com/att/EELF.
EELF abstracts your choice of logging provider, and decorates the familiar Logger contracts with features like:
- Localization.
- Error codes.
- Generated wiki documentation.
- Separate audit, metrics,
securityerror and debug logs.
EELF is a facade, so logging output is configured in two ways:
- By selection of a logging provider such as Logback or Log4j, typically via the classpath.
- By way of a provider configuration document, typically logback.xml or log4j.xml. See 48534506.
SLF4J
SLF4J is a logging facade, and a humble masterpiece. It combines what's common to all major, modern Java logging providers into a single interface. This decouples the caller from the provider, and encourages the use of what's universal, familiar and proven.
EELF also logs via SLF4J's abstractions as the default provider.
Providers
Logging providers are normally enabled by their presence in the classpath. This means the decision may have been made for you, in some cases implicitly by dependencies. If you have a strong preference then you can change providers, but since the implementation is typically abstracted behind EELF or SLF4J, it may not be worth the effort.
Logback
Logback is the most commonly used provider. It is generally configured by an XML document named logback.xml. See 48534506.
See HELM template https://git.onap.org/logging-analytics/tree/reference/provider/helm/logback
Log4j 2.X
Log4j 2.X is somewhat less common than Logback, but equivalent. It is generally configured by an XML document named log4j.xml. See 48534506.
Log4j 1.X
Strongly discouraged from Beijing onwards, since 1.X is EOL, and since it does not support escaping, so its output may not be machine-readable. See https://logging.apache.org/log4j/1.2/.
This affects OpenDaylight-based components like SDNC and APPC, since ODL releases prior to Carbon bundled Log4j 1.X, and make it difficult to replace. The Common Controller SDK Project project targets ODL Carbon, so remaining instances of Log4j 1.X should disappear by the time of the Casablanca release.
What to Log
The purpose of logging is to capture diagnostic information.
An important aspect of this is analytics, which requires tracing of requests between components. In a large, distributed and scalable system such as ONAP this is critical to understanding behavior and performance.
General
It isn't the aim of this document to reiterate Best Practices, so advice here is general:
- Use a logging facade such as SLF4J or EELF.
- Write log messages in English.
- Write meaningful messages. Consider what will be useful to consumers of logger output.
- Log at the appropriate level. Be aware of the volume of logs that will be produced.
- Safeguard the information in exceptions, and ensure it is never lost.
- Use error codes to characterize exceptions.
- Log in a machine-readable format. See Conventions.
- Log for analytics as well as troubleshooting.
Others have written extensively on this:
- http://www.masterzen.fr/2013/01/13/the-10-commandments-of-logging/
- https://www.loggly.com/blog/how-to-write-effective-logs-for-remote-logging/
- And so on.
Standard Attributes
These are attributes common to all log messages. They are either:
- Explicitly required by logging APIs:
- Logger
- Level
- Message
- Exception (note that exception is the only standard attribute that may routinely be empty).
- Implicitly derived by the logging provider:
- Timestamp
- Thread.
Which means you normally can't help but report them.
See https://www.slf4j.org/api/org/slf4j/Logger.html and https://logback.qos.ch/manual/layouts.html#ClassicPatternLayout for their origins and use.
Logger Name
This indicates the name of the logger that logged the message.
In Java it is convention to name the logger after the class or package using that logger.
- In Java, report the class or package name.
- In Python, the class or source filename.
Most other languages will fit one of those patterns.
Level
Severity, typically drawn from the enumeration {TRACE, DEBUG, INFO, WARN, ERROR}.
Think carefully about the information you report at each log level. The default log level is INFO.
Some loggers define non-standard levels, like FINE, FINER, WARNING, SEVERE, FATAL or CRITICAL. Use these judiciously, or avoid them.
Message
The free text payload of a log event.
This is the most important item of information in most log messages. See 48534506 guidelines.
Internationalization
Diagnostic log messages generally do not need to be internationalized.
Parameterization
Parameterized messages allow serialization to be deferred until AFTER level threshold checks. This means the cost is never incurred for messages that won't be written.
- Favor parameterized messages, especially for INFO and DEBUG logging.
- Perform expensive serialization in the #toString method of wrapper classes.
For example:
Code Block | ||
---|---|---|
| ||
logger.debug("Relax - this won't hurt: {}", new ToStringWrapper(costlyToSerialize)); |
Exception
The error stacktrace, where applicable.
Log unabridged stacktraces upon error.
When rethrowing, ensure that frame information is not lost:
- By logging the original exception at the point where it was caught.
- By setting the original exception as the cause when rethrowing.
Timestamp
Logged as an ISO8601 UTC datetime. Millisecond (or greater) precision is preferable.
For example:
Code Block | ||
---|---|---|
| ||
2018-07-05T20:21:34.794Z |
Offset timestamps are OK provided the offset is included. (In the above example, the "Z" is a shorthand indicating an offset of zero – UTC).
Thread
The name of the thread from which the log message was emitted.
Thread names don't necessarily convey useful information, and their reliability depends on the thread model implemented by different runtimes, but they are sometimes used in heuristic analysis.
Efficiency
There is tension between utility and efficiency. IO bandwidth is finite, and the cost of serialization can be significant, especially at higher diagnostic levels.
Methods and Line Numbers
Many loggers can use reflection to emit the originating (Java) method, and even individual line numbers.
This information is certainly useful, but very expensive. Most logging implementations recommend that this not be enabled in production.
Level Thresholds
Level indicates severity.
Logger output is typically filtered by logger and level. The default logging level is INFO, so particular consideration should be given to the efficiency of INFO-level logging.
When DEBUG-level logging is configured, it's probably for good reason, and a greater overhead is expected. Be aware that it's not unusual for DEBUG logging to be left enabled inadvertently, however.
WARN and ERROR-level messages are of higher value, and comparatively rare, so their cost is less of a concern.
Conditionals
A common pattern is to place conditionals around (expensive) serialization.
For example:
Code Block | ||
---|---|---|
| ||
if (logger.isDebugEnabled()) {
logger.debug("But this WILL hurt: " + costlyToSerialize);
} |
Parameterized logging is preferable.
Context
MDCs
A Mapped Diagnostic Context (MDC) allows an arbitrary string-valued attribute to be attached to a Java thread via a ThreadLocal variable. The MDC's value is then emitted with each message logged by that thread. The set of MDCs associated with a log message is serialized as unordered name-value pairs (see 48534506).
A good discussion of MDCs can be found at https://logback.qos.ch/manual/mdc.html.
Example
From Luke Parker's call graph work in https://git.onap.org/logging-analytics/tree/reference/logging-slf4j-demo
Code Block | ||
---|---|---|
| ||
LogEntry(markers=ENTRY, logger=ComponentAlpha, requestID=eb3e0dc2-6c3c-4bb7-8ed6-e5cc4ec7aad2, invocationID=06c815ef-5969-45cc-b319-d0dbcde89329, timestamp=Tue May 08 04:23:27 AEST 2018) |
Mapped Diagnostic Context Table
- Must be set as early in invocation as possible.
- Must be unset on exit.
- keep in sync with https://wiki.acumos.org/display/OAM/Log+Standards
Pipe Order | Name | Type | Group | Description | Applicable (per log file) | Marker Associations | Moved MDC to standard attribute | Removed (was in older spec) | Required? Y/N/C (C= context dependent) N = not required L=Library provided | Derived | Historical | Acumos ref | Use Cases | Code References |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | LogTimestamp | log system | use %d field - see %d{"yyyy-MM-dd'T'HH:mm:ss.SSSXXX",UTC} | L | ||||||||||
2 | EntryTimestamp | MDC | if part of an ENTRY marker log | C | ||||||||||
3 | InvokeTimestamp | MDC | if part of an INVOKE marker log | C | ||||||||||
4 | MDC | UUID to track |
...
VNF/PNF context dependent - on CRUD operations of VNF/PNFs
The IDs that need to be covered with the above Attributes are
- VNF_ID OR VNFC_ID : (Unique identifier for a VNF asset that is being instantiated or that would generate an alarms)
- VSERVER_ID OR VM_ID (or vmid): (Unique identified for a virtual server or virtual machine on which a Control Loop action is usually taken on, or that is installed as part of instantiation flow)
- PNF : (What is the Unique identifier used within ONAP)
...
This field can be used to capture the flow of a transaction through the system by indicating the components and operations involved in processing. If present, it can be denoted by a comma separated list of components and applications.
Discussion: should be redundant because of the invocationID
...
N-20180419
Review 1 more more time on Tue.
Logging
Via SLF4J:
Code Block | ||||
---|---|---|---|---|
| ||||
import java.util.UUID;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
// ...
final Logger logger = LoggerFactory.getLogger(this.getClass());
MDC.put("SomeUUID", UUID.randomUUID().toString());
try {
logger.info("This message will have a UUID-valued 'SomeUUID' MDC attached.");
// ...
}
finally {
MDC.clear();
} |
EELF doesn't directly support MDCs, but its default provider (where com.att.eelf.configuration.SLF4jWrapper is the configured EELF provider)normally logs via SLF4J, and SLF4J will receive any MDC that is set:
Code Block | ||||
---|---|---|---|---|
| ||||
import java.util.UUID;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
// ...
final EELFLogger logger = EELFManager.getInstance().getLogger(this.getClass());
MDC.put("SomeUUID", UUID.randomUUID().toString());
try {
logger.info("This message will have a UUID-valued 'SomeUUID' MDC attached.");
// ...
}
finally {
MDC.clear();
} |
Serializing
Output of MDCs must ensure that:
- All reported MDCs are logged with both name AND value. Logging output should not treat any MDCs as special.
- All MDC names and values are escaped.
Escaping in Logback configuration can be achieved with:
Code Block | ||||
---|---|---|---|---|
| ||||
%replace(%replace(%mdc){'\t','\\\\t'}){'\n','\\\\n'} |
MDC - RequestID
This is often referred to by other names, including "Transaction ID", and one of several (pre-standardization) REST header names including X-ECOMP-RequestID and X-ONAP-RequestID.
...
the processing of each client request across all the ONAP components involved in its processing |
...
Y | In general | |||||||||||||
5 | InvocationID | MDC | UUID correlates log entries relating to a single invocation of a single component | Y | ||||||||||
6 | InstanceID | MDC | UUID to differentiate between multiple instances of the same (named) log writing service/application | Y | was InstanceUUID | |||||||||
7 | ServiceInstanceID | MDC | C | |||||||||||
8 | thread | log system | use %thread field | L | ||||||||||
9 | ServiceName | The service inside the partner doing the call - includes API name | Y | |||||||||||
10 | PartnerName | unauthenticated = The part of the URI specifying the agent that the caller used to make the call to the component that is logging the message. authenticated = userid
| Y | user | ||||||||||
11 | StatusCode | This field indicates the high level status of the request - one of (COMPLETE, ERROR, INPROGRESS) | Y | 20180807: expand from 2 fields to add "INPROGRESS" addresses Chris Lott question on https://wiki.acumos.org/display/OAM/Log+Standards | ||||||||||
12 | ResponseCode | This field contains application-specific error codes. | Y | |||||||||||
13 | ResponseDesc | This field contains a human readable description of the ResponseCode | Y | |||||||||||
14 | level | %level | L | |||||||||||
15 | Severity | Logging level by default aligned with the reported log level - one of INFO/TRACE/DEBUG/WARN/ERROR/FATAL | Y | level (but numbers) | ||||||||||
16 | ServerIPAddress | C | ||||||||||||
17 | ElapsedTime | C | ||||||||||||
18 | ServerFQDN | The VM FQDN if the server is virtualized. Otherwise the host name of the logging component. | Y | |||||||||||
19 | ClientIPAddress | This field contains the requesting remote client application’s IP address if known. Otherwise empty. | Y | |||||||||||
20 | VirtualServerName | C | ||||||||||||
21 | ContextName | C | ||||||||||||
22 | TargetEntity | The name of the ONAP component or sub-component, or external entity, at which the operation activities captured in this metrics log record is invoked. | C | |||||||||||
23 | TargetServiceName | The name of the API or operation activities invoked (name on the remote/target application) at the TargetEntity. | C | |||||||||||
24 | TargetElement | VNF/PNF context dependent - on CRUD operations of VNF/PNFs The IDs that need to be covered with the above Attributes are - VNF_ID OR VNFC_ID : (Unique identifier for a VNF asset that is being instantiated or that would generate an alarms) - VSERVER_ID OR VM_ID (or vmid): (Unique identified for a virtual server or virtual machine on which a Control Loop action is usually taken on, or that is installed as part of instantiation flow) - PNF : (What is the Unique identifier used within ONAP) | C | |||||||||||
25 | User | MDC | User - used for %X{user} | C | ||||||||||
26 | p_logger | log system | The name of the class doing the logging (in my case the ApplicationController – close to the targetservicename but at the class granular level - this field is %logger | L | ||||||||||
27 | p_mdc | log system | allows forward compatability with ELK indexers that read all MDCs in a single field - while maintaining separate MDCs above. The key/value pairs all in one pipe field (will have some duplications currently with MDC’s that are in their own pipe – but allows us to expand the MDC list – replaces customvalue1-3 older fields - this field is %mdc | L | ||||||||||
28 | p_message | log system | The marker labels INVOKE, ENTRY, EXIT – and later will also include DEBUG, AUDIT, METRICS, ERROR when we go to 1 log file - this field is %marker | L | ||||||||||
29 | p_marker | log system | The marker labels INVOKE, ENTRY, EXIT – and later will also include DEBUG, AUDIT, METRICS, ERROR when we go to 1 log file - this field is %marker | L |
Logging
Via SLF4J:
Code Block | ||||
---|---|---|---|---|
| ||||
import java.util.UUID;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
// ...
final Logger logger = LoggerFactory.getLogger(this.getClass());
MDC.put("SomeUUID", UUID.randomUUID().toString());
try {
logger.info("This message will have a UUID-valued 'SomeUUID' MDC attached.");
// ...
}
finally {
MDC.clear();
} |
EELF doesn't directly support MDCs, but its default provider (where com.att.eelf.configuration.SLF4jWrapper is the configured EELF provider)normally logs via SLF4J, and SLF4J will receive any MDC that is set:
Code Block | ||||
---|---|---|---|---|
| ||||
import java.util.UUID;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import com.att.eelf.configuration.EELFLogger;
import com.att.eelf.configuration.EELFManager;
// ...
final EELFLogger logger = EELFManager.getInstance().getLogger(this.getClass());
MDC.put("SomeUUID", UUID.randomUUID().toString());
try {
logger.info("This message will have a UUID-valued 'SomeUUID' MDC attached.");
// ...
}
finally {
MDC.clear();
} |
Serializing
Output of MDCs must ensure that:
- All reported MDCs are logged with both name AND value. Logging output should not treat any MDCs as special.
- All MDC names and values are escaped.
Escaping in Logback configuration can be achieved with:
Code Block | ||||
---|---|---|---|---|
| ||||
%replace(%replace(%mdc){'\t','\\\\t'}){'\n','\\\\n'} |
MDC - RequestID
This is often referred to by other names, including "Transaction ID", and one of several (pre-standardization) REST header names including X-TransactionID, X-ECOMP-TransactionID, X-ECOMP-RequestID and X-ONAP-RequestID.
ONAP logging uses a universally unique "RequestID" value in log records to track the processing of each client request across all the ONAP components involved in its processing. RequestID be propagated across all interfaces, not just REST Interfaces.
This value:
- Is logged as a RequestID MDC.
- Is propagated between components in REST calls as an X-ONAP-RequestID HTTP header.
Receiving the X-ONAP-RequestID will vary by component according to APIs and frameworks. In general:
Code Block | ||||
---|---|---|---|---|
| ||||
import javax.ws.rs.core.HttpHeaders;
// ...
final HttpHeaders headers = ...;
// ...
String txId = headers.getRequestHeaders().getFirst("X-ONAP-RequestID");
if (StringUtils.isBlank(txId)) {
txId = UUID.randomUUID().toString();
}
MDC.put("RequestID", txID); |
Setting the X-ONAP-RequestID likewise will vary. For example:
Code Block | ||||
---|---|---|---|---|
| ||||
final String txID = MDC.get("RequestID");
HttpURLConnection cx = ...;
// ...
cx.setRequestProperty("X-ONAP-RequestID", txID); |
Note that it's been suggested that for the duration of Casablanca we report the request ID using all three headers:
- X-ONAP-RequestID (canonical)
- X-RequestID (deprecated)
- X-TransactionID (deprecated)
MDC - InvocationID
InvocationID is similar to RequestID, but where RequestID correlates records relating a single, top-level invocation of ONAP as it traverses many systems, InvocationID correlates log entries relating to a single invocation of a single component. Typically this means via REST, but in certain cases an InvocationID may be allocated without a new invocation, e.g. when a request is retried.
RequestID and InvocationID allow an execution graph to be derived. This requires that:
- The relationship between RequestID and InvocationID is reported.
- The relationship between caller and recipient is reported for each invocation.
The proposed approach is that:
- Callers:
- Issue a new, unique InvocationID UUID for each downstream call they make.
- Log the new InvocationID, indicating the intent to invoke:
- With Markers INVOKE, and SYNCHRONOUS if the invocation is synchronous.
- With their own InvocationID still set as an MDC.
- Pass the InvocationID as an X-InvocationID REST header.
- Invoked components:
- Retrieve the InvocationID from REST headers upon invocation, or generate a UUID default.
- Set the InvocationID MDC.
- Write a log entry with the Marker ENTRY. (In EELF this will be to the AUDIT log).
- Act as per Callers in all downstream requests.
- Write a log entry with the Marker EXIT upon return. (In EELF this will be to the METRICS log).
- Unset all MDCs on exit.
That seems onerous, but:
- It's only a few calls.
- It can be largely abstracted in the case of EELF logging.
MDC - InstanceID
(formerly InstanceUUID)
If known, this field contains a universally unique identifier used to differentiate between multiple instances of the same (named) log writing service/application. Its value is set at instance creation time (and read by it, e.g., at start/initialization time from the environment). This value should be picked up by the component instance from its configuration file and subsequently used to enable differentiation of log records created by multiple, locally load balanced ONAP component or subcomponent instances that are otherwise identically configured.
Handles parallel threads or running across a load balanced set of microservices - for identification.
MDC - PartnerName
This field should contain the name of the client application user agent or user invoking the API. The identification of the entity that made the request being served. For a serving API that is authenticating the request, this should be the authenticated username or equivalent (e.g. a userid or a mechid).
For example SDC-BE instead of just SDC for the overall pods
This is often used for heuristic analysis to identify invocations between ONAP individual ONAP components. Its value has never been clearly stipulated, so a common problem has been a lack of consistency.
There is no clear consensus, but:
- Use the short name of your component, e.g. xyzdriver. (try to incorporate both levels - the container name and the pod the container is in within the kubernetes deployment)
- Values should be human-readable.
- Values should be fine-grained enough to disambiguate subcomponents where it's likely to matter. This is subjective.
- Be consistent: your component should ALWAYS report same value.
Real-life examples include MSO, bpmnclient, BPELClient, (all of which are reported by SO), openECOMP (SDNC), vid (VID!) etc. (See the problem?)
Usage overlaps with InvocationID, which doesn't mean PartnerName gets retired, but which might mean it serves a more descriptive purpose. (Since it hasn't proven to be a great way of generating a call graph).
MDC - ServiceName
The URI that the caller used to make the call to the component that is logging the message.
For EELF Audit log records that capture API requests, this field contains the name of the API invoked at the component creating the record (e.g., Layer3ServiceActivateRequest).
For EELF Audit log records that capture processing as a result of receipt of a message, this field should contain the name of the module that processes the message.
Usage is the same for indexable logs.
MDC - StatusCode
This field indicates the high level status of the request. It must have the value COMPLETE when the request is successful and ERROR when there is a failure. And INPROGRESS for states between the two.
Discussion: status/response/severity relationship
status = global, response below is app specific
Ability to render severity-like line in a non-debug log
MDC - ResponseCode
This field contains application-specific error codes. For consistency, common error categorizations should be used.
MDC - Severity
OPS specific
Use/Map existing https://www.slf4j.org/api/org/apache/commons/logging/Log.html
ENUM is INFO/TRACE/DEBUG/WARN/ERROR/FATAL
By default - align this severity with the reported log level
(optionally a way to map actual level from reported level if required)
MDC - ServerFQDN
This field contains the Virtual Machine (VM) Fully Qualified Domain Name (FQDN) if the server is virtualized. Otherwise, it contains the host name of the logging component.
Best effort (ip, fqdn)
(previously covered by removed "Server" field)
redundancy between clientIP, server, virtualServer name is OK - and helpfull for runtime OPS/Hybrid envs
supercedes virtualServerName
Report what is in the http header
Discussion: roll all 3 fqdn, hostname or ip into one field - do we ever need two of the 3 fields concurrently?
TODO: Verify what is also available from a filebeat agent when it exists
MDC - ClientIPAddress
This field contains the requesting remote client application’s IP address if known. Otherwise this field can be empty.
We don't differentiate between inside/outside ONAP for the IP - this supports hybrid environments
Derived from the system
redundancy between clientIP, server, virtualServer name is OK - and helpfull for runtime OPS/Hybrid envs
Discussion: do we need both ip and fqdn fields?
Report what is in the http header
MDC - EntryTimestamp
Date-time that processing activities being logged begins. The value should be represented in UTC and formatted per ISO 8601, such as “2015-06-03T13:21:58+00:00”. The time should be shown with the maximum resolution available to the logging component (e.g., milliseconds, microseconds) by including the appropriate number of decimal digits. For example, when millisecond precision is available, the date-time value would be presented as, as “2015-06-03T13:21:58.340+00:00”.
Context dependent on whether part of an ENTRY marker
Audit requires this field
MDC - InvokeTimestamp
Timestamp on invocation start.
Context dependent on whether part of an INVOKE marker
metrics needs this field.
MDC - TargetEntity
It contains the name of the ONAP component or sub-component, or external entity, at which the operation activities captured in this metrics log record is invoked.
Example: SDC-BE
MDC - TargetServiceName
It contains the name of the API or operation activities invoked (name on the remote/target application) at the TargetEntity.
Example: Class name of rest endpoint
Discussion: on building call graph vs human readable single line - keep for human readable
Used as valuable URI - to annnote invoke marker
Review in terms of 48534506 - possiblly add INVOKE-return - to filter reporting
TBD: Coverage by log file type (debug, trace, ...)
TBD: cover off discussion on reducing log files to two (DEBUG/rest) for C* release
MDC - TargetElement
VNF/PNF context dependent - on CRUD operations of VNF/PNFs
The IDs that need to be covered with the above Attributes are
- VNF_ID OR VNFC_ID : (Unique identifier for a VNF asset that is being instantiated or that would generate an alarms)
- VSERVER_ID OR VM_ID (or vmid): (Unique identified for a virtual server or virtual machine on which a Control Loop action is usually taken on, or that is installed as part of instantiation flow)
- PNF : (What is the Unique identifier used within ONAP)
MDCs - the Rest
Other MDCs are logged in a wide range of contexts.
Certain MDCs and their semantics may be specific to EELF log types.
Deprecation
Indexing makes many of the remaining attributes redundant. So for example:
- There is considerable duplication:
- BeginTimestamp, EndTimestamp, ElapsedTime. These are all captured elsewhere (and ElapsedTime is even redundant within that triplet).
- Server, ServerIPAddress, ServerFQDN, VirtualServiceName. Overkill. Should be one, plus optionally ClientIPAddress (or some variant thereof).
- TargetEntity, TargetServiceName, not obviously different to similar attributes.
- There is junk:
- Severity? Nagios codes?
- ProcessKey?
- All the stuff that's already grayed out in the table above.
- People may defend these individually, maybe vigorously, but they're domain-specific:
- That absolutely doesn't mean they can't be used.
- Beats configuration allows ad hoc contexts to be indexed.
- But perhaps they don't belong in this kind of spec.
- Redundant attributes *do* matter, because:
- Populating and propagating everything prescribed by the guide approaches being prohibitive. People won't do it, and people *don't* do it.
- If something might be in one of several attributes then that's worse than it being in just one.
- That means:
- We're left with only two MANDATORY attributes, necessary to build invocations graphs:
- RequestID - top-level transactions.
- InvocationID - inter-component invocations.
- And a minimal number of OPTIONAL descriptive attributes: ServiceInstanceID, InstanceID, Server, StatusCode, ResponseCode, ResponseDescription.
- Those are the ones we need to document clearly, support in APIs, etc.
- That's <=10, a manageable number.
- And again, that matters because if the number isn't manageable, people won't (and don't) comply.
Some of that is contentious, but it's just talking points at this stage. We've tiptoed around the issue of extant conventions, and the ongoing result is a lot of attributes that nobody's really sure how to use, and which don't result in better logs. In Casablanca it's time to be less conservative.
Examples
Markers
Markers unambiguously assign semantics to individual log messages. They allow messages that have a specific meaning to be cheaply and easily identified in logger output, without inherently unreliable (and more costly, and less easily enforced) schemes like scanning for magic strings in the text of each log message.
ONAP logging requires the emission of Markers reporting entry, exit and invocation as the execution of requests pass between ONAP components. This information is used to generate a call graph.
ONAP components are also free to use Markers for their own purposes. Any Markers that are logged will be automatically indexed by Logstash.
Markers differ from MDCs in two important ways:
- They have a name, but no value. They are a tag - like a label.
- They are specified explicitly on invocation. They are not ThreadLocal, and they do not propagate.
EELF's implementation can be modified to emit Markers, but its public APIs do not allow them to be passed in by callers.
see code on reference folder in git clone ssh://michaelobrien@gerrit.onap.org:29418/logging-analytics
Examples
Marker formatting is using tabs -
Jira | ||||||
---|---|---|---|---|---|---|
|
Note there are 3 tabs (see p_mak in logback.xml) delimiting the MARKERS (ENTRY and EXIT) at the end of each line
<property name="p_mak" value="%replace(%replace(%marker){'\t', '\\\\t'}){'\n','\\\\n'}"/>
Code Block | ||||
---|---|---|---|---|
| ||||
2018-07-05T20:21:34.794Z http-nio-8080-exec-2 INFO org.onap.demo.logging.ApplicationService InstanceID=ede7dd52-91e8-45ce-9406-fbafd17a7d4c, RequestID=f9d8bb0f-4b4b-4700-9853-d3b79d861c5b, ServiceName=/logging-demo/rest/health/health, InvocationID=8f4c1f1d-5b32-4981-b658-e5992f28e6c8, InvokeTimestamp=2018-07-05T20:21:26.617Z, PartnerName=, ClientIPAddress=0:0:0:0:0:0:0:1, ServerFQDN=localhost ENTRY
2018-07-05T20:22:09.268Z http-nio-8080-exec-2 INFO org.onap.demo.logging.ApplicationService ResponseCode=, InstanceID=ede7dd52-91e8-45ce-9406-fbafd17a7d4c, RequestID=f9d8bb0f-4b4b-4700-9853-d3b79d861c5b, ServiceName=/logging-demo/rest/health/health, ResponseDescription=, InvocationID=8f4c1f1d-5b32-4981-b658-e5992f28e6c8, Severity=, InvokeTimestamp=2018-07-05T20:21:26.617Z, PartnerName=, ClientIPAddress=0:0:0:0:0:0:0:1, ServerFQDN=localhost, StatusCode= EXIT
|
This value:
- Is logged as a RequestID MDC.
- Is propagated between components in REST calls as an X-TransactionID HTTP header.
Receiving the X-TransactionID will vary by component according to APIs and frameworks. In general:
Code Block | ||||
---|---|---|---|---|
| ||||
import javax.ws.rs.core.HttpHeaders;
// ...
final HttpHeaders headers = ...;
// ...
String txId = headers.getRequestHeaders().getFirst("X-TransactionID");
if (StringUtils.isBlank(txId)) {
txId = UUID.randomUUID().toString();
}
MDC.put("RequestID", txID); |
Setting the X-TransactionID likewise will vary. For example:
Code Block | ||||
---|---|---|---|---|
| ||||
final String txID = MDC.get("RequestID");
HttpURLConnection cx = ...;
// ...
cx.setRequestProperty("X-TransactionID", txID); |
MDC - InvocationID
InvocationID is similar to RequestID, but where RequestID correlates records relating a single, top-level invocation of ONAP as it traverses many systems, InvocationID correlates log entries relating to a single invocation of a single component. Typically this means via REST, but in certain cases an InvocationID may be allocated without a new invocation, e.g. when a request is retried.
RequestID and InvocationID allow an execution graph to be derived. This requires that:
- The relationship between RequestID and InvocationID is reported.
- The relationship between caller and recipient is reported for each invocation.
The proposed approach is that:
- Callers:
- Issue a new, unique InvocationID UUID for each downstream call they make.
- Log the new InvocationID, indicating the intent to invoke:
- With Markers INVOKE, and SYNCHRONOUS if the invocation is synchronous.
- With their own InvocationID still set as an MDC.
- Pass the InvocationID as an X-InvocationID REST header.
- Invoked components:
- Retrieve the InvocationID from REST headers upon invocation, or generate a UUID default.
- Set the InvocationID MDC.
- Write a log entry with the Marker ENTRY. (In EELF this will be to the AUDIT log).
- Act as per Callers in all downstream requests.
- Write a log entry with the Marker EXIT upon return. (In EELF this will be to the METRIC log).
- Unset all MDCs on exit.
That seems onerous, but:
...
MDC - PartnerName
This field should contain the name of the client application user agent or user invoking the API. The identification of the entity that made the request being served. For a serving API that is authenticating the request, this should be the authenticated username or equivalent (e.g. a userid or a mechid).
This is often used for heuristic analysis to identify invocations between ONAP individual ONAP components. Its value has never been clearly stipulated, so a common problem has been a lack of consistency.
There is no clear consensus, but:
- Use the short name of your component, e.g. xyzdriver. (try to incorporate both levels - the container name and the pod the container is in within the kubernetes deployment)
- Values should be human-readable.
- Values should be fine-grained enough to disambiguate subcomponents where it's likely to matter. This is subjective.
- Be consistent: your component should ALWAYS report same value.
Real-life examples include MSO, bpmnclient, BPELClient, (all of which are reported by SO), openECOMP (SDNC), vid (VID!) etc. (See the problem?)
Usage overlaps with InvocationID, which doesn't mean PartnerName gets retired, but which might mean it serves a more descriptive purpose. (Since it hasn't proven to be a great way of generating a call graph).
MDC - ServiceName
The URI that the caller used to make the call to the component that is logging the message.
For EELF Audit log records that capture API requests, this field contains the name of the API invoked at the component creating the record (e.g., Layer3ServiceActivateRequest).
For EELF Audit log records that capture processing as a result of receipt of a message, this field should contain the name of the module that processes the message.
Usage is the same for indexable logs.
MDCs - the Rest
Other MDCs are logged in a wide range of contexts.
Certain MDCs and their semantics may be specific to EELF log types.
Deprecation
Indexing makes many of the remaining attributes redundant. So for example:
- There is considerable duplication:
- BeginTimestamp, EndTimestamp, ElapsedTime. These are all captured elsewhere (and ElapsedTime is even redundant within that triplet).
- Server, ServerIPAddress, ServerFQDN, VirtualServiceName. Overkill. Should be one, plus optionally ClientIPAddress (or some variant thereof).
- TargetEntity, TargetServiceName, not obviously different to similar attributes.
- There is junk:
- Severity? Nagios codes?
- ProcessKey?
- All the stuff that's already grayed out in the table above.
- People may defend these individually, maybe vigorously, but they're domain-specific:
- That absolutely doesn't mean they can't be used.
- Beats configuration allows ad hoc contexts to be indexed.
- But perhaps they don't belong in this kind of spec.
- Redundant attributes *do* matter, because:
- Populating and propagating everything prescribed by the guide approaches being prohibitive. People won't do it, and people *don't* do it.
- If something might be in one of several attributes then that's worse than it being in just one.
- That means:
- We're left with only two MANDATORY attributes, necessary to build invocations graphs:
- RequestID - top-level transactions.
- InvocationID - inter-component invocations.
- And a minimal number of OPTIONAL descriptive attributes: ServiceInstanceID, InstanceUUID, Server, StatusCode, ResponseCode, ResponseDescription.
- Those are the ones we need to document clearly, support in APIs, etc.
- That's <=10, a manageable number.
- And again, that matters because if the number isn't manageable, people won't (and don't) comply.
Some of that is contentious, but it's just talking points at this stage. We've tiptoed around the issue of extant conventions, and the ongoing result is a lot of attributes that nobody's really sure how to use, and which don't result in better logs. In Casablanca it's time to be less conservative.
Examples
SDC-BE
Markers
Markers unambiguously assign semantics to individual log messages. They allow messages that have a specific meaning to be cheaply and easily identified in logger output, without inherently unreliable (and more costly, and less easily enforced) schemes like scanning for magic strings in the text of each log message.
ONAP logging requires the emission of Markers reporting entry, exit and invocation as the execution of requests pass between ONAP components. This information is used to generate a call graph.
ONAP components are also free to use Markers for their own purposes. Any Markers that are logged will be automatically indexed by Logstash.
Markers differ from MDCs in two important ways:
- They have a name, but no value. They are a tag - like a label.
- They are specified explicitly on invocation. They are not ThreadLocal, and they do not propagate.
EELF's implementation can be modified to emit Markers, but its public APIs do not allow them to be passed in by callers.
...
Logging
Via SLF4J:
Code Block | ||||
---|---|---|---|---|
| ||||
import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.slf4j.Marker; import org.slf4j.MarkerFactory; // ... final Logger logger = LoggerFactory.getLogger(this.getClass()); final Marker marker = MarkerFactory.getMarker("MY_MARKER"); logger.warn(marker, "This warning has a 'MY_MARKER' annotation."); |
...
It can be automatically reported by EELF, and written to the METRIC METRICS log.
It must be manually set otherwise.
...
InvokeTimestamp context dependent MDC will be reported here.
SLF4J:
Code Block | ||||||
---|---|---|---|---|---|---|
| ||||||
TBD |
...
This should accompany INVOKE when the invocation is synchronous.
SLF4J:
Code Block | ||||||
---|---|---|---|---|---|---|
| ||||||
public static final Marker INVOKE_SYNCHRONOUS; static { INVOKE_SYNCHRONOUS = MarkerFactory.getMarker("INVOKE"); INVOKE_SYNCHRONOUS.add(MarkerFactory.getMarker("SYNCHRONOUS")); } // ... // Generate and report invocation ID. final String invocationID = UUID.randomUUID().toString(); MDC.put(MDC_INVOCATION_ID, invocationID); try { logger.debug(INVOKE_SYNCHRONOUS, "Invoking synchronously ... "); } finally { MDC.remove(MDC_INVOCATION_ID); } // Pass invocationID as HTTP X-InvocationID header. callDownstreamSystem(invocationID, ... ); |
EELF example of SYNCHRONOUS reporting, without changing published APIs.
...
Error Codes
Errorcodes Error codes are reported as MDCs.
TODO: add to table
Exceptions should be accompanied by an errrorcodeerror code. Typically this is achieved by incorporating errorcodes error codes into your exception hierarchy and error handling. ONAP components generally do not share this kind of code, though EELF defines a marker interface (meaning it has no methods) EELFResolvableErrorEnum.
A common convention is for errorcodes error codes to have two components:
- A prefix, which identifies the origin of the error.
- A suffix, which identifies the kind of error.
...
- Logs should be human-readable (within reason).
- Shipper and indexing performance and durability depends on logs that can be parsed quickly and reliably.
- Consistency means fewer shipping and indexing rules are required.
Text Output
TODO: 20190115 - do not take the example in this section until I reverify it in terms of the reworked spec example in
...
Jira | ||||||
---|---|---|---|---|---|---|
|
...
ONAP needs to strike a balance between human-readable and machine-readable logs. This means:
...
EELF guidelines stipulate that an application should output log records to four separate files:
- audit
- metricmetrics
- error
- debug
This applies only to EELF logging. Components which log directly to a provider may choose to emit the same set of logs, but most do not.
...
Suboperations invoked as part of the processing of the API request are logged in the Metrics log. For example, when a call is made to another ONAP component or external (i.e., non-ONAP) entity, a Metrics log record captures that call. In such a case, the Metrics log record indicates (among other things) the time the call is made, when it returns, the entity that is called, and the API invoked on that entity. The Metrics log record contain the same RequestID as the Audit log record so the two can be correlated.
Note that a single request may result in multiple Audit log records at an ONAP component and may result in multiple Metrics log records generated by the component when multiple suboperations are required to satisfy the API request captured in the Audit log record.
Error Log
An error log is required for EELF-enabled components, and is intended to capture info, warn, error and fatal conditions sensed (“exception handled”) by the software components.
Debug Log
A debug log is optional for EELF-enabled components, and is intended to capture whatever data may be needed to debug and correct abnormal conditions of the application.
Engine.out
...
the call is made, when it returns, the entity that is called, and the API invoked on that entity. The Metrics log record contain the same RequestID as the Audit log record so the two can be correlated.
Note that a single request may result in multiple Audit log records at an ONAP component and may result in multiple Metrics log records generated by the component when multiple suboperations are required to satisfy the API request captured in the Audit log record.
Error Log
An error log is required for EELF-enabled components, and is intended to capture info, warn, error and fatal conditions sensed (“exception handled”) by the software components.
This includes previous logs that went to application.log
Debug Log
A debug log is optional for EELF-enabled components, and is intended to capture whatever data may be needed to debug and correct abnormal conditions of the application.
Engine.out
Console logging may also be present, and is intended to capture “system/infrastructure” records. That is stdout and stderr assigned to a single “engine.out” file in a directory configurable (e.g. as an environment/shell variable) by operations personnel.
Application Log (deprecated)
see example in https://git.onap.org/oom/tree/kubernetes/portal/charts/portal-sdk/resources/config/deliveries/properties/ONAPPORTALSDK/logback.xml
We no longer support this 5th log file - see error.log
Log File Locations
There are several locations where logs are available on the host, on the nfs share and in each application and filebeat container
Logs on each Kubernetes host VM - docker empty.dir shares
Logs on the /dockerdata-nfs share across hosts
Logs on each microservice docker container - /var/log/onap
Logs on each filebeat docker container sidecar - /var/log/onap
Excerpt |
---|
New ONAP Component ChecklistAdd this procedure to the Project Proposal Template By following a few simple rules:
Obligations fall into two categories:
You must:
|
...
|
...
|
...
|
...
They are unordered. |
What's New
(Including what WILL be new in v1.2 / R2).
...
In addition, we expect to provide (as a Beijing deliverable) a minimal, synthetic component as an example of best-practices, and this will provide all code examples for this guide. (Does that mean the example will log via EELF, or will we end up with two variants?)
Pending Specification Work
id | date | item | details | status |
---|---|---|---|---|
20180614 | MDC ClientIPAddress | Ask question of OPS to remove this field - 20180419 | todo | |
20180614 | MDC ResponseCode / ResponseDescription | expand/find note 1* | todo |
Developer Guide
see separate page (cross releases) in Logging Developer Guide