Public issue detail

Runaway CPU investigation for postgres: file not found retry at XLogNeedsFlush

postgres is stuck in a likely file not found retry loop: 2.27% of sampled CPU passed through XLogNeedsFlush, with repeated thread backtraces show 1 thread(s) around 0x00007f8ccb7fc687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1

Last seen: 2026-09-30 03:07 UTC. Public JSON: /v1/issues/01a0ee1d-0385-77b3-8bf7-d516edc62f39

Technical snapshot

This is the clearest retained userspace thread cluster Fixer captured while the process was spinning.

Representative thread backtrace

  • Command: /usr/lib/postgresql/16/bin/postgres -D /tmp/postgis-pg16.72AZTy/data -F -h -p 30426 -k /tmp/postgis-pg16.72AZTy/socket -c fsync=off -c full_page_writes=off -c synchronous_commit=off
  • Why Fixer classified it this way: The trace keeps retrying file lookups that fail with ENOENT, which suggests a missing-file retry loop.
  • Thread summary: thread backtraces show 1 thread(s) around 0x00007f8ccb7fc687 in __GI__IO_flush_all () from target:<path>
  • Contention signals: event-loop-wakeups, gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory. warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable. Connect to gdbserver inside the container. warning: Expected absolute pathname for libpthread in the inferior, but got target:<path> warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  • Repeated loop: fstat -> read -> read
  • Top syscalls: read x24869, fstat x23953, rt_sigprocmask x22121, openat x13511
  • Kernel: 7.1.8+deb14.1-amd64
  • Distribution: debian
0x00007f8ccb7fc687 in __GI__IO_flush_all () from target:<path>
0x00007f8ccb7fc6ad in __GI__IO_flush_all () from target:<path>
0x00007f8ccb87da6d in epoll_wait () from target:<path>
0x000055e591f1cf5b in WaitEventSetWait ()
0x000055e591eb5745 in ?? ()
0x000055e591eb847c in PostmasterMain ()
0x000055e591bdd4ec in main ()

Possible duplicates

These are suggestions based on sanitized trigram similarity plus structured fields like package, subsystem, classification, and wait site. They are not auto-merged.

Runaway CPU investigation for postgres: file not found retry at next_uptodate_folio

possible duplicate

postgres is stuck in a likely file not found retry loop: 4.33% of sampled CPU passed through next_uptodate_folio, with repeated thread backtraces show 1 thread(s) around 0x00007f6114aba687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-14source: linuxscore: 106reports: 3successful triagesimilarity: 99%

Why this looks related: same classification, same subsystem, same target, same wait site

Last seen: 2026-10-12 08:43 UTC. Public page: /issues/019d3a17-b958-7a60-86fd-5304e697f42c. Public JSON: /v1/issues/019d3a17-b958-7a60-86fd-5304e697f42c

Runaway CPU investigation for postgres: file not found retry at _dl_map_new_object

possible duplicate

postgres is stuck in a likely file not found retry loop: 1.58% of sampled CPU passed through _dl_map_new_object, with repeated thread backtraces show 1 thread(s) around 0x00007fb038f9c687 in __GI__IO_flush_all () from target:<path>.

highpackage: postgresql-18source: postgresql-18score: 106reports: 1similarity: 99%

Why this looks related: same classification, same subsystem, same target, same wait site

Last seen: 2026-10-21 03:01 UTC. Public page: /issues/019f9e46-ed87-7693-a004-3c6b0b260a51. Public JSON: /v1/issues/019f9e46-ed87-7693-a004-3c6b0b260a51

Runaway CPU investigation for postgres: file not found retry at malloc

possible duplicate

postgres is stuck in a likely file not found retry loop: 1.84% of sampled CPU passed through malloc, with repeated thread backtraces show 1 thread(s) around 0x00007f85b973a687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-10-13 06:02 UTC. Public page: /issues/01a133a7-70dc-73b3-b590-4cd62ec20ac9. Public JSON: /v1/issues/01a133a7-70dc-73b3-b590-4cd62ec20ac9

Runaway CPU investigation for postgres: file not found retry at WaitEventSetWait

possible duplicate

postgres is stuck in a likely file not found retry loop: 28.57% of sampled CPU passed through WaitEventSetWait, with repeated thread backtraces show 1 thread(s) around 0x00007f7f64417687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same subsystem, same target, same wait site, very similar public summary

Last seen: 2026-09-28 15:51 UTC. Public page: /issues/01a0e840-352c-74f0-a516-88ac9cf0a1d0. Public JSON: /v1/issues/01a0e840-352c-74f0-a516-88ac9cf0a1d0

Runaway CPU investigation for postgres: file not found retry at __strncat_avx2_rtm

possible duplicate

postgres is stuck in a likely file not found retry loop: 2.74% of sampled CPU passed through __strncat_avx2_rtm, with repeated thread backtraces show 1 thread(s) around 0x00007f5f4a5c8687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1similarity: 99%

Why this looks related: same classification, same subsystem, same target, very similar public summary

Last seen: 2026-10-02 08:38 UTC. Public page: /issues/01a0f645-98ad-79e2-91aa-24280b548c45. Public JSON: /v1/issues/01a0f645-98ad-79e2-91aa-24280b548c45

Runaway CPU investigation for postgres: file not found retry at pglz_decompress

possible duplicate

postgres is stuck in a likely file not found retry loop: 3.77% of sampled CPU passed through pglz_decompress, with repeated thread backtraces show 1 thread(s) around 0x00007f92e0a4e687 in __GI__IO_flush_all () from target:<path>.

highscore: 106reports: 1similarity: 93%

Why this looks related: same classification, same subsystem, same target

Last seen: 2026-10-13 05:43 UTC. Public page: /issues/019fa653-58fc-7d62-b84f-1f51afcbf926. Public JSON: /v1/issues/019fa653-58fc-7d62-b84f-1f51afcbf926

Published attempts

No public attempts have been published for this issue yet.

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