From 53aa26eddc772a6719bf0da64b0684c333294d05 Mon Sep 17 00:00:00 2001 From: reivilibre Date: Mon, 3 Jul 2023 10:38:57 +0000 Subject: [PATCH] Add a timeout that aborts any Postgres statement taking more than 1 hour. (#15853) * Add a timeout to Postgres statements * Newsfile Signed-off-by: Olivier Wilkinson (reivilibre) --------- Signed-off-by: Olivier Wilkinson (reivilibre) --- changelog.d/15853.misc | 1 + synapse/storage/engines/postgres.py | 13 +++++++++++++ 2 files changed, 14 insertions(+) create mode 100644 changelog.d/15853.misc diff --git a/changelog.d/15853.misc b/changelog.d/15853.misc new file mode 100644 index 000000000..3e9516b1a --- /dev/null +++ b/changelog.d/15853.misc @@ -0,0 +1 @@ +Add a timeout that aborts any Postgres statement taking more than 1 hour. \ No newline at end of file diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py index b350f57cc..05a72dc55 100644 --- a/synapse/storage/engines/postgres.py +++ b/synapse/storage/engines/postgres.py @@ -45,6 +45,15 @@ class PostgresEngine( psycopg2.extensions.register_adapter(bytes, _disable_bytes_adapter) self.synchronous_commit: bool = database_config.get("synchronous_commit", True) + # Set the statement timeout to 1 hour by default. + # Any query taking more than 1 hour should probably be considered a bug; + # most of the time this is a sign that work needs to be split up or that + # some degenerate query plan has been created and the client has probably + # timed out/walked off anyway. + # This is in milliseconds. + self.statement_timeout: Optional[int] = database_config.get( + "statement_timeout", 60 * 60 * 1000 + ) self._version: Optional[int] = None # unknown as yet self.isolation_level_map: Mapping[int, int] = { @@ -157,6 +166,10 @@ class PostgresEngine( if not self.synchronous_commit: cursor.execute("SET synchronous_commit TO OFF") + # Abort really long-running statements and turn them into errors. + if self.statement_timeout is not None: + cursor.execute("SET statement_timeout TO ?", (self.statement_timeout,)) + cursor.close() db_conn.commit()