From 618d405a322590d022d839b6d72ba51e992a71c3 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 3d8da48f2..02d71302e 100644 --- a/synapse/storage/util/id_generators.py +++ b/synapse/storage/util/id_generators.py @@ -618,14 +618,7 @@ 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: