Alexander Kukushkin 6cff5a3e08 Smart replication feedback ... This commit makes psycopg2 responsible for sending the status update (feedback) messages to the server regardless of whether a synchronous or asynchronous connection is used. Feedback is sent every *status_update* (default value is 10) seconds, which could be configured by passing a corresponding parameter to the `start_replication()` or `start_replication_expert()` methods. The actual feedback message is sent by the `pq_read_replication_message()` when the *status_update* timeout is reached. The default behavior of the `send_feedback()` method is changed. It doesn't send a feedback message on every call anymore but just updates internal structures. There is still a way to *force* sending a message if *force* or *reply* parameters are set. The new approach has certain advantages: 1. The client can simply call the `send_feedback()` for every processed message and the library will take care of not overwhelming the server. Actually, in the synchronous mode it is even mandatory to confirm every processed message. 2. The library tracks internally the pointer of the last received message which is not keepalive. If the client confirmed the last message and after that server sends only keepalives with increasing *wal_end*, the library can safely move forward *flush* position to the *wal_end* and later automatically report it to the server. Reporting of the *wal_end* received from keepalive messages is very important. Not doing so casing: 1. Excessive disk usage, because the replication slot prevents from WAL being cleaned up. 2. The smart and fast shutdown of the server could last indefinitely because walsender waits until the client report *flush* position equal to the *wal_end*. This implementation is only extending the existing API and therefore should not break any of the existing code.		2019-05-06 10:27:44 +02:00
..
__init__.py	Copyright year updated	2019-02-17 01:36:36 +00:00
_ipaddress.py	Copyright year updated	2019-02-17 01:36:36 +00:00
_json.py	Use PY2, PY3 for conditional code instead of sys.version_info	2019-03-16 19:54:40 +00:00
_lru_cache.py	Use a proper LRU cache for namedtuples	2019-02-02 19:29:20 +00:00
_range.py	Copyright year updated	2019-02-17 01:36:36 +00:00
compat.py	Added PY2, PY3 to compat module	2019-03-16 19:54:40 +00:00
errorcodes.py	Copyright year updated	2019-02-17 01:36:36 +00:00
errors.py	SQLSTATE error classes implemented in C	2019-02-10 03:45:14 +00:00
extensions.py	Remove unnecessary except ImportError for Python datetime types	2019-03-16 16:35:51 +00:00
extras.py	Smart replication feedback	2019-05-06 10:27:44 +02:00
pool.py	Allow 0 as key in the pool	2019-03-17 18:24:50 +00:00
sql.py	Use PY2, PY3 for conditional code instead of sys.version_info	2019-03-16 19:54:40 +00:00
tz.py	Copyright year updated	2019-02-17 01:36:36 +00:00