[prathamesh04]

Closes MDEV-39307

Problem

The audit plugin built its log timestamp from a time_t value with second
resolution only (event.general_time), so the %f specifier in
server_audit_timestamp_format always rendered 000000. The server already
fetched a precise my_hrtime() once per query in
LOGGER::general_log_write(), but downcast it to seconds before passing it
to audit plugins.

Fix

Per review feedback, the server now forwards its high-resolution time
through the audit API instead of the plugin re-fetching it at write time:

• mysql_event_general gains general_time_microseconds (in microseconds
  since the epoch), appended at the end of the struct; general_time keeps
  second resolution for backward compatibility. Interface version bumped to
  MYSQL_AUDIT_INTERFACE_VERSION 0x0304.
• mysql_audit_general_log() now takes my_hrtime_t and forwards the full
  value (sql/log.cc no longer downcasts via hrtime_to_time).
• The error/result/status events in mysql_audit_general() fill the new
  field from a single my_hrtime() call.
• The server_audit plugin uses event->general_time_microseconds for
  query log entries. Connection and table events carry no timestamp in the
  audit API, so the plugin takes the time at event time for those entries
  (one fetch per event).

This addresses the review comment: the timestamp is fetched once by the
server per event, and the plugin no longer calls my_hrtime() at write
time.

Tests

mysql-test/suite/plugins/server_audit_timestamp:

• section 2l now expects six zero-padded digits for %f
• new section 10 logs 20 statements and verifies a real (non-zero)
  microsecond value is written

Verified locally: mtr --suite=plugins server_audit_timestamp plus the
full server_audit* suite passes, and the audit log shows varying
microsecond values (e.g. US=721344).

[prathamesh04]

@vuvova @sanja-byelkin — this fixes MDEV-39307 (audit plugin %f always renders 000000). Added an MTR testcase to server_audit_timestamp as the reporter requested. MCA signed.

[gkodinov]

Thank you for your contribution! This is a preliminary review.

From a preliminary technical PoV the contributions is correct. So I'm going to let it go to final review.

However, I feel strongly that the fix should be dome somewhat otherwise. See below on how I think it should be done.

Anyway, clarify this with the final reviewer please.

In case you agree with him to stay on the current course, then it's a bug fix and as such needs to go to the lowest affected version instead of the main branch.

[Copilot]

Pull request overview

This PR fixes %f microseconds rendering in the server_audit plugin timestamp by switching log timestamp generation from second-resolution time_t values to microsecond-resolution my_hrtime() and propagating the microsecond component via MYSQL_TIME::second_part.

Changes:

• Update write_log() to derive timestamp seconds from hrtime_to_time(my_hrtime()) and microseconds from hrtime_sec_part(), so %f outputs real microseconds.
• Remove now-unused second-resolution timestamp plumbing (time_t parameters/fields and time() callsites) from the audit log call chain.
• Extend the server_audit_timestamp MTR test to expect 6 digits for %f and add a new section verifying at least one non-zero microsecond value is logged.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
plugin/server_audit/server_audit.cc	Switch audit log timestamping to my_hrtime() and set MYSQL_TIME::second_part for %f; remove unused time_t plumbing.
mysql-test/suite/plugins/t/server_audit_timestamp.test	Update %f expectations and add a new test section that asserts non-zero microseconds appear.
mysql-test/suite/plugins/r/server_audit_timestamp.result	Update expected output to match the new %f behavior and new test section output.

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[gkodinov]

FYI: According to our development cycle we work on bugs In the following periods 15 Mar-30 Apr, 15 Jun-30 Jul, 15 Sep-30 Oct and 15 Dec-31 Jan. So, please, expect to get a review somewhere between these two dates and the goal is to have your PR merged before the second date

[prathamesh04]

@gkodinov thank you for the review. I reworked the fix as you suggested: the server now forwards its high-resolution time through the audit API instead of the plugin re-fetching my_hrtime() at write time.

• mysql_audit_general_log() now takes my_hrtime_t (sql/log.cc:1669 passes current_time directly, no more hrtime_to_time downcast).
• mysql_event_general gained general_time_microseconds (appended at the end of the struct, general_time keeps second resolution for backward compatibility), MYSQL_AUDIT_INTERFACE_VERSION bumped to 0x0304.
• The error/result/status events in mysql_audit_general() fill it from a single my_hrtime() call.
• server_audit now uses event->general_time_microseconds for query entries; connection/table events have no server timestamp in the audit API, so the plugin takes the time once per event for those.

Since this is now an API extension rather than a bug fix to existing code, main remains the target branch.

Could the final reviewer please confirm this approach?

[prathamesh04]

Note on the remaining red buildbot: the only failing builder is amd64-ubuntu-2204-debug-ps, and its failure is unrelated to this change.

• The failing test is rpl.rpl_row_foreign_key_mdl, a replication test that is a known sporadic failure on the buildbot (sync_with_master timeout), tracked in MDEV-39023. It does not exercise the audit plugin or any code touched here.
• main.cte_update_delete and perfschema.bad_option only trigger the informational --check-testcases notice (a server variable changed during the test), not a result mismatch; both pass locally.

The ABI failure that affected the other builders was fixed by regenerating the include/mysql/plugin_audit.h.pp canon; all 15 other buildbots now pass.

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Suppressed comments (1)

plugin/server_audit/server_audit.cc:1119

• thd_gmt_sec_to_TIME() takes a my_time_t (server-defined time type). Casting to time_t here can unnecessarily narrow/truncate the seconds value on platforms where time_t differs, and it’s inconsistent with the function signature. Cast to my_time_t instead (and keep constants as ULL to avoid implicit narrowing).

      MYSQL_TIME ltime;
      thd_gmt_sec_to_TIME(NULL, &ltime, (time_t) (ts_us / 1000000));
      ltime.second_part= (ulong) (ts_us % 1000000);