Re: WAL files keep piling up

Thanks for responding. On current master it looks like so:

ls pg_xlog/archive_status/ | grep ready | wc -l
0

ls pg_xlog/archive_status/ | grep done | wc -l
501

Kind regards.

śr., 22 gru 2021 o 19:01 Ninad Shah <nshah(dot)postgres(at)gmail(dot)com> napisał(a):

> A stupid question. How many .ready files are there?
>
>
> Regards,
> Ninad Shah
>
> On Wed, 22 Dec 2021 at 21:04, Zbigniew Kostrzewa <zkostrzewa(at)gmail(dot)com>
> wrote:
>
>> Hi,
>>
>> I have a PostgreSQL (9.6.15) two node cluster setup with Patroni. The
>> instances are configured to work in master <-> synchronous standby setup
>> and both run in docker containers with pgdata volume mounted from host.
>> When master is restarted the synchronous standby automatically takes the
>> role of master and master starts operating as synchronous replica.
>>
>> Everything works fine but whenever I restart master instance it creates a
>> new wal file in pg_xlog/ however old wal files are not cleaned up. They
>> pile up and in my reproduction environment, where there are no operations
>> on the database, they currently occupy:
>> du -sh pg_xlog/
>> 17G pg_xlog/
>>
>> and the number of the files is more or less:
>> ls pg_xlog/ | grep -v history | wc -l
>> 1024
>>
>> I've searched through the mailing lists and articles like
>> https://dataegret.com/2018/04/pg_wal-is-too-big-whats-going-on/ and the
>> main problems mentioned in most of the places are:
>> 1. failing archive command
>> 2. abandoned (inactive) replication slot
>> 3. issues with checkpoints
>> 3. too big wal_keep_segments value
>>
>> However, none of those problems seem to apply to my deployment:
>> 1. I have `archive_mode` set to `off`
>> 1a. I even tried enabling it and setting the `archive_command` to
>> '/bin/true' just to confirm a suggestion found in one of the post on the
>> mailing list (that didn't improve anything)
>> 2. the only replication slot in `pg_replication_slots` is the one related
>> to the synchronous replica and it is active
>> 3. I've enabled `log_checkpoint` but doesn't see any errors or warnings
>> related to checkpoints triggered either automatically or manually via
>> `CHECKPOINT;`
>> 4. `wal_keep_segments` is set to 8 and `max_wal_size` is set to 1GB
>>
>> Is there anything that I should check that could shed some light on this?
>>
>> A few configuration options taken from `pg_settings`:
>> archive_command = (disabled)
>> archive_mode = off
>> archive_timeout = 0
>> check_function_bodies = on
>> checkpoint_completion_target = 0.5
>> checkpoint_flush_after = 32
>> checkpoint_timeout = 300
>> hot_standby = on
>> hot_standby_feedback = off
>> max_replication_slots = 10
>> max_wal_senders = 10
>> max_wal_size = 64
>> min_wal_size = 5
>> synchronous_commit = on
>> synchronous_standby_names = patroni1
>> wal_block_size = 8192
>> wal_buffers = 512
>> wal_compression = off
>> wal_keep_segments = 8
>> wal_level = replica
>> wal_log_hints = on
>> wal_receiver_status_interval = 10
>> wal_receiver_timeout = 60000
>> wal_retrieve_retry_interval = 5000
>> wal_segment_size = 2048
>> wal_sender_timeout = 60000
>> wal_sync_method = fdatasync
>> wal_writer_delay = 200
>> wal_writer_flush_after = 128
>>
>> Kind regards
>>
>