poorbarcode opened a new pull request, #19302: URL: https://github.com/apache/pulsar/pull/19302
### Motivation In the PR https://github.com/apache/pulsar/pull/9302, the property backlog size of each subscription returned in the response of the API topics stats, by default this property is always equal to 0 in response, and this will confuse users. Since the calculation of backlog size is done in broker memory, there is no significant overhead(the process is described in the following section), so I think the correct values should be displayed by default. #### Discuss in mail list - https://lists.apache.org/thread/wvjrp3co9fyl596onwv037944kdz000d #### The following two APIs should be affected: In Pulsar admin API ``` pulsar-admin topics stats persistent://test-tenant/ns1/tp1 --get-subscription-backlog-size pulsar-admin topics stats persistent://test-tenant/ns1/tp1 -sbs ``` the default value of parameter `--get-subscription-backlog-size` will be `true` In Pulsar Rest API ``` curl GET "http://127.0.0.1:8080/test-tenant/ns1/tp1/stats?subscriptionBacklogSize=true"; ``` the default value of the parameter `subscriptionBacklogSize` will be `true` #### The following is the process of calculating backlog size: - Divide `PersistentTopc.ledgers` into two parts according to the ledgerId of the mark delete position of the cursor. The second part is ledgers indicating the messages still need to be consumed, aka backlogSizeInLedgers. - Find the LedgerInfo whose ledgerId is the same as the ledgerId of the mark delete position of the cursor, and we can also divide the ledger into two parts, the second part is entries indicating the messages still need to be consumed, multiply the average size of each entry in metrics by the number of still need to be consumed entries we can get the backlog size in this ledger. aka backlogSizeInEntries. - `backlogSizeInLedgers` + `backlogSizeInEntries` ### Modifications Make the default value of param "--get-subscription-backlog-size" of admin API "topics stats" `true` ### Documentation <!-- DO NOT REMOVE THIS SECTION. CHECK THE PROPER BOX ONLY. --> - [ ] `doc` <!-- Your PR contains doc changes. Please attach the local preview screenshots (run `sh start.sh` at `pulsar/site2/website`) to your PR description, or else your PR might not get merged. --> - [ ] `doc-required` <!-- Your PR changes impact docs and you will update later --> - [x] `doc-not-needed` <!-- Your PR changes do not impact docs --> - [ ] `doc-complete` <!-- Docs have been already added --> ### Matching PR in forked repository PR in forked repository: - https://github.com/poorbarcode/pulsar/pull/54 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
