Fix type codec cache races #301
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1st1
reviewed
May 31, 2018
asyncpg/connection.py
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| self._protocol.get_settings().register_data_types(types) | ||
| need_reprepare = False | ||
| types_with_missing_codecs = statement._init_types() | ||
| while types_with_missing_codecs: |
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Need a MAX_ITER constant and raise an exception if we loop more times than it (in case we have a bug in out logic that will make it easier for people to report it)
1st1
reviewed
May 31, 2018
asyncpg/connection.py
Outdated
| @@ -326,6 +332,11 @@ def is_in_transaction(self): | |||
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| return statement | |||
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| async def _introspect_types(self, typeoids, timeout): | |||
| types, intro_stmt = await self.__execute( | |||
Current global type codec cache works poorly in a pooled environment. The global nature of the cache makes introspection/cache bust race a frequent occurrence. Additionally, busting the codec cache in _all_ connections only because one of them had reconfigured a codec seems wrong. The fix is simple: every connection now has its own codec cache. The downside is that there will be more introspection queries on fresh connections, but given that most connections in the field are pooled, the robustness gains are more important. Fixes: #278
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Current global type codec cache works poorly in a pooled environment.
The global nature of the cache makes introspection/cache bust race a
frequent occurrence. Additionally, busting the codec cache in all
connections only because one of them had reconfigured a codec seems
wrong.
The fix is simple: every connection now has its own codec cache. The
downside is that there will be more introspection queries on fresh
connections, but given that most connections in the field are pooled,
the robustness gains are more important.
Fixes: #278