Initial Findings
It is found that the current Patch operation in CPS core can only update value of leaf nodes under a container node at a time.
Issues & Decisions:
Notes | Decisions |
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As per discussion with stakeholder (DT), the following decisions were made:
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After discussion in the CPS-sub team, following conclusions were made:
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| After the investigation it was found that the reason behind the inconsistencies discovered was lack of support for Patch operation for multiple data nodes. As per discussion in CPS sub team daily call it was decided to bring in support for Patch operation for multiple data nodes. As it would address all the inconsistencies discovered. |
JSON Data Stored in CPS DB using POST operation.
The following JSON data was first stored in CPS DB:
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{ "multiple-data-tree:interface-A": { "host-name": "host", "interface": [ { "name": "Interface-A", "address": "10.10.10.1", "subnet-mask": "255.255.255.0", "enabled": false } ], "domain": "false" }, "multiple-data-tree:interface-B": { "interface": [ { "name": "Interface-B", "address": "10.10.10.1", "subnet-mask": "255.255.255.0" } ] } } |
Analysis of Patch operation (Update node leaves)
Currently after multiple data trees are stored in CPS DB. On performing the Patch operation, with root node xpath "/", the first data tree is only updated by the Patch operation. To test this following scenarios were performed:
Updating all data trees under an anchor with root node xPath "/"
Code Block title CURL request to update multiple leaves across multiple data trees collapse true curl --location --request PATCH 'http://localhost:8080/cps/api/v1/dataspaces/testDataspace/anchors/sample/nodes?xpath=%2F' --header 'Content-Type: application/json' --header 'Accept: application/json' --header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' --header 'Cookie: JSESSIONID=node0iyclt1syzfqj28jzo5qc5gks1.node0' \ --data '{ "multiple-data-tree:interface-A": { "host-name": "host-A", //value to be updated "interface": [ { "name": "Interface-A", "address": "10.10.10.100", "subnet-mask": "255.255.255.25", "enabled": false } ], "domain": "true" }, "multiple-data-tree:interface-B": { "interface": [ { "name": "Interface-B", "address": "10.10.10.100", //value to be updated "subnet-mask": "255.255.255.0" //value to be updated } ] } }'
Code Block title Response: 500 Server Error collapse true { "status": "500 INTERNAL_SERVER_ERROR", "message": "could not execute statement; SQL [n/a]; nested exception is org.hibernate.exception.DataException: could not execute statement", "details": "Check logs for details." }
Reason: The following scenario would fail because CPS Patch operation only supports updating multiple leaves under one container node at a time. And here when we try to update multiple leaves present in two different containers the operations fails.
Code Block title On performing Get operation we get the following JSON data, here none of the leaves are updated collapse true [ { "int:interface-A": { "domain": "false", "host-name": "host", "interface": [ { "name": "Interface-A", "address": "10.10.10.1", "enabled": false, "subnet-mask": "255.255.255.0" } ] } }, { "int:interface-B": { "interface": [ { "name": "Interface-B", "address": "10.10.10.1", "subnet-mask": "255.255.255.0" } ] } } ]
Updating the data trees individually, leads to successful updation
When updating multiple leaves present under individual data nodes the operation successfully executes.Code Block title CURL request to update leaves under container data node collapse true curl --location --request PATCH 'http://localhost:8080/cps/api/v1/dataspaces/testDataspace/anchors/sample/nodes?xpath=%2F' \ --header 'Content-Type: application/json' --header 'Accept: application/json' --header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' --header 'Cookie: JSESSIONID=node0iyclt1syzfqj28jzo5qc5gks1.node0' \ --data '{ "int:interface-A": { "domain": "true", //value to be updated "host-name": "Host-A" //value to be updated } }'
Response 200 OK
Code Block title Updated data after making get request collapse true [ { "int:interface-A": { "domain": "true", //updated "host-name": "Host-A", //updated "interface": [ { "name": "Interface-A", "address": "10.10.10.200", "enabled": true, "subnet-mask": "255.255.255.0" } ] } } ]
Code Block title CURL request to update leaves of one list item in a list data node collapse true curl --location --request PATCH 'http://localhost:8080/cps/api/v1/dataspaces/testDataspace/anchors/sample/nodes?xpath=%2Finterface-B' \ --header 'Content-Type: application/json' --header 'Accept: application/json' --header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' --header 'Cookie: JSESSIONID=node0iyclt1syzfqj28jzo5qc5gks1.node0' \ --data '{ "int:interface": { "name": "Interface-B", "address": "10.10.10.200", //value to be updated "subnet-mask": "255.255.255.10" //value to be updated } }'
Response 200 OK
Code Block title Updated data after making get request collapse true [ { "int:interface-B": { "interface": [ { "name": "Interface-B", "address": "10.10.10.200", //updated "subnet-mask": "255.255.255.10" //updated } ] } } ]
Inconsistencies with Patch Operation
When updating multiple data trees with only leaf nodes
Assuming the following data is in the data base, having one leaf in each data tree
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{ "first-container": { "a-leaf": "a-value" }, "last-container": { "x-leaf": "x-value" } } |
An update operation is performed on both data trees as follows:
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curl --location --request PATCH 'http://localhost:8080/cps/api/v1/dataspaces/testDataspace/anchors/multipleDataTree/nodes?xpath=%2F' --header 'Content-Type: application/json' --header 'Accept: application/json' --header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' --header 'Cookie: JSESSIONID=node0kglnliqz1tzc1g0x6opgrphei0.node0' \ --data '{ "first-container": { "a-leaf": "a-new-value" }, "last-container": { "x-leaf": "x-new-value" } }' |
On performing a get operation, it is noticed that only first data tree gets updated
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[ { "multiple-data-tree:last-container": { "x-leaf": "x-new-value" } }, { "multiple-data-tree:first-container": { "a-leaf": "a-value" } } ] |