diff options
| -rw-r--r-- | src/backend/postmaster/walsummarizer.c | 32 |
1 files changed, 19 insertions, 13 deletions
diff --git a/src/backend/postmaster/walsummarizer.c b/src/backend/postmaster/walsummarizer.c index 191b360bef4..c1dd75b98c2 100644 --- a/src/backend/postmaster/walsummarizer.c +++ b/src/backend/postmaster/walsummarizer.c @@ -388,13 +388,27 @@ WalSummarizerMain(char *startup_data, size_t startup_data_len) /* * If we've reached the switch LSN, we can't summarize anything else - * on this timeline. Switch to the next timeline and go around again. + * on this timeline. Switch to the next timeline and go around again, + * backing up to the exact switch point if we passed it. */ if (!XLogRecPtrIsInvalid(switch_lsn) && current_lsn >= switch_lsn) { + /* Restart summarization from switch point. */ current_tli = switch_tli; + current_lsn = switch_lsn; + + /* Next timeline and switch point, if any, not yet known. */ switch_lsn = InvalidXLogRecPtr; switch_tli = 0; + + /* Update (really, rewind, if needed) state in shared memory. */ + LWLockAcquire(WALSummarizerLock, LW_EXCLUSIVE); + WalSummarizerCtl->summarized_lsn = current_lsn; + WalSummarizerCtl->summarized_tli = current_tli; + WalSummarizerCtl->lsn_is_exact = true; + WalSummarizerCtl->pending_lsn = current_lsn; + LWLockRelease(WALSummarizerLock); + continue; } @@ -415,7 +429,6 @@ WalSummarizerMain(char *startup_data, size_t startup_data_len) /* Update state in shared memory. */ LWLockAcquire(WALSummarizerLock, LW_EXCLUSIVE); - Assert(WalSummarizerCtl->pending_lsn <= end_of_summary_lsn); WalSummarizerCtl->summarized_lsn = end_of_summary_lsn; WalSummarizerCtl->summarized_tli = current_tli; WalSummarizerCtl->lsn_is_exact = true; @@ -1060,7 +1073,6 @@ SummarizeWAL(TimeLineID tli, XLogRecPtr start_lsn, bool exact, /* Also update shared memory. */ LWLockAcquire(WALSummarizerLock, LW_EXCLUSIVE); - Assert(summary_end_lsn >= WalSummarizerCtl->pending_lsn); Assert(summary_end_lsn >= WalSummarizerCtl->summarized_lsn); WalSummarizerCtl->pending_lsn = summary_end_lsn; LWLockRelease(WALSummarizerLock); @@ -1460,17 +1472,11 @@ summarizer_read_local_xlog_page(XLogReaderState *state, * Allow reads up to exactly the switch point. * * It's possible that this will cause read_upto to move - * backwards, because walreceiver might have read a - * partial record and flushed it to disk, and we'd view - * that data as safe to read. However, the - * XLOG_END_OF_RECOVERY record will be written at the end - * of the last complete WAL record, not at the end of the - * WAL that we've flushed to disk. - * - * So switchpoint < private->read_upto is possible here, - * but switchpoint < state->EndRecPtr should not be. + * backwards, because we might have been promoted before + * reaching the end of the previous timeline. In that case, + * the next loop iteration will likely conclude that we've + * reached end of WAL. */ - Assert(switchpoint >= state->EndRecPtr); private_data->read_upto = switchpoint; /* Debugging output. */ |