From 20fa83f3744b25e513fdc904261c87c324bbc87e Mon Sep 17 00:00:00 2001 From: Erik Johnston Date: Wed, 14 Oct 2020 15:40:06 +0100 Subject: [PATCH] Remove racey assertion in MultiWriterIDGenerator (#8530) We asserted that the IDs returned by postgres sequence was greater than any we had seen, however this is technically racey as we may update the current positions out of order. We now assert that the sequences are correct on startup, so the assertion is no longer really required, so we remove them. --- changelog.d/8530.bugfix | 1 + synapse/storage/util/id_generators.py | 7 ------- 2 files changed, 1 insertion(+), 7 deletions(-) create mode 100644 changelog.d/8530.bugfix diff --git a/changelog.d/8530.bugfix b/changelog.d/8530.bugfix new file mode 100644 index 000000000..443d88424 --- /dev/null +++ b/changelog.d/8530.bugfix @@ -0,0 +1 @@ +Fix rare bug where sending an event would fail due to a racey assertion. diff --git a/synapse/storage/util/id_generators.py b/synapse/storage/util/id_generators.py index ad017207a..eccd2d5b7 100644 --- a/synapse/storage/util/id_generators.py +++ b/synapse/storage/util/id_generators.py @@ -612,14 +612,7 @@ class _MultiWriterCtxManager: db_autocommit=True, ) - # Assert the fetched ID is actually greater than any ID we've already - # seen. If not, then the sequence and table have got out of sync - # somehow. with self.id_gen._lock: - assert max(self.id_gen._current_positions.values(), default=0) < min( - self.stream_ids - ) - self.id_gen._unfinished_ids.update(self.stream_ids) if self.multiple_ids is None: