From 93a028f569232fa498279841cb61ad11c2df5c85 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Thu, 24 Jul 2014 14:32:34 +0200 Subject: [PATCH] Properly remove ephemeral replication slots after a crash restart. Ephemeral slots - slots that shouldn't survive database restarts - weren't properly cleaned up after a immediate/crash restart. They were ignored in the sense that they weren't restored into memory and thus didn't cause unwanted resource retention; but they prevented a new slot with the same name from being created. Now ephemeral slots are fully removed during startup. Backpatch to 9.4 where replication slots where added. --- src/backend/replication/slot.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c index 5671ac1d14f..b374c6eccf5 100644 --- a/src/backend/replication/slot.c +++ b/src/backend/replication/slot.c @@ -1192,6 +1192,24 @@ RestoreSlotFromDisk(const char *name) (errmsg("replication slot file %s: checksum mismatch, is %u, should be %u", path, checksum, cp.checksum))); + /* + * If we crashed with an ephemeral slot active, don't restore but delete + * it. + */ + if (cp.slotdata.persistency != RS_PERSISTENT) + { + sprintf(path, "pg_replslot/%s", name); + + if (!rmtree(path, true)) + { + ereport(WARNING, + (errcode_for_file_access(), + errmsg("could not remove directory \"%s\"", path))); + } + fsync_fname("pg_replslot", true); + return; + } + /* nothing can be active yet, don't lock anything */ for (i = 0; i < max_replication_slots; i++) { @@ -1206,10 +1224,6 @@ RestoreSlotFromDisk(const char *name) memcpy(&slot->data, &cp.slotdata, sizeof(ReplicationSlotPersistentData)); - /* Don't restore the slot if it's not parked as persistent. */ - if (slot->data.persistency != RS_PERSISTENT) - return; - /* initialize in memory state */ slot->effective_xmin = cp.slotdata.xmin; slot->effective_catalog_xmin = cp.slotdata.catalog_xmin;