Noisy logging from docdb transaction cache lookup loops · yugabyte/yugabyte-db#28908

2025-10-10T20:47:33.000Z

Jira Link: [DB-18631](https://yugabyte.atlassian.net/browse/DB-18631) The transaction cache lookup code has a tight retry loop on transaction status lookup, but logs during a cache lookup retry at WARNING level which is too high volume for a cache miss. This might actually be logging so aggressively that it impacts performance in extreme cases. Specifically [this](https://github.com/yugabyte/yugabyte-db/blob/master/src/yb/docdb/transaction_status_cache.cc#L146) should be a VLOG(5) (since below logging the results of the lookup is a VLOG(4) Conversely [this](https://github.com/yugabyte/yugabyte-db/blob/master/src/yb/docdb/transaction_status_cache.cc#L156) should be a WARNING not an INFO [DB-18631]: https://yugabyte.atlassian.net/browse/DB-18631?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

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good first issuejira-originatedkind/new-featurepriority/low

Description

Jira Link: DB-18631

The transaction cache lookup code has a tight retry loop on transaction status lookup, but logs during a cache lookup retry at WARNING level which is too high volume for a cache miss. This might actually be logging so aggressively that it impacts performance in extreme cases.

Specifically this should be a VLOG(5) (since below logging the results of the lookup is a VLOG(4) Conversely this should be a WARNING not an INFO

Contributor guide

Tech stack: cpp
Domain: backenddatabase
Issue type: performance
Difficulty: 2
Estimated time: under 1 hour
Activity status: blocked
Clarity: clear
Prerequisites: None
Newbie friendliness: 30
Research direction: The issue is in `/src/yb/docdb/transaction status cache.cc`. Lines 146 and 156 need log level adjustments: line 146 should change from WARNING to VLOG(5), and line 156 should change from INFO to WARNING. The fix is straightforward and localized to this file.