Tignor, Tom ttignor at akamai.com
Mon Feb 1 06:06:56 PST 2016
	Jan,
	Thanks much for all the help. I’ve been looking over logswitch finish and
the event and changelog tables. Selecting logswitch_finish() on one of my
replicas simply returned ""Slony-I: log switch to sl_log_2 still in
progress - sl_log_1 not truncated” All three seem to be in that state with
either sl_log_1 or sl_log_2. Looking closer at sl_event and sl_log_2 I’m
seeing some strangeness.

ams=# select min(pg_catalog.txid_snapshot_xmin(ev_snapshot)),
max(pg_catalog.txid_snapshot_xmin(ev_snapshot)) from _ams_cluster.sl_event
where ev_origin = 1;
    min    |    max
-----------+-----------
 139136948 | 139204299
(1 row)


ams=# select min(log_txid), max(log_txid) from _ams_cluster.sl_log_2 where
log_origin = 1;
    min    |    max
-----------+-----------
 631532717 | 631661386
(1 row)


ams=#


	So I understand all the txids referenced in sl_event are in the 139M
range while all those in sl_log_2 are in the 631M range. Normally, the
sl_log txids should be older, shouldn’t they? Do you think I’ve hit a
txid-wraparound problem?

	Tom    :-)



On 1/28/16, 1:09 PM, "Jan Wieck" <jan at wi3ck.info> wrote:

>On 01/28/2016 11:11 AM, Tignor, Tom wrote:
>>
>> 	Output below. They seem to be replicating normally, except for the
>>sl_log
>> growth.
>
>Indeed. Is there anything in the slon logs for those nodes that says why
>it doesn't finish the log switch?
>
>Connect to the database as a the slony user.
>
>To check if a log switch is indeed in progress, do
>
>     SELECT last_value FROM _ams_cluster.sl_log_status;
>
>It should be either 2 or 3. If it is 0 or 1, no log switch is in
>progress and you can start one with
>
>     SELECCT _ams_cluster.logswitch_start();
>
>If it is 2 or 3, then you can do
>
>     SELECT _ams_cluster.logswitch_finish();
>
>All these operations are harmless and will only do what is safely
>possible. Look at the code of logswitch_finish() to find out how it
>determines if the current log switch can be finished. In short, the
>cleanup thread is removing events from sl_event that have been confirmed
>by all nodes in the cluster. The function logswitch_finish() looks if
>there is anything left in sl_event, that belonged to that old log. If so
>it will not finish. Running those queries manually you can find out what
>that event is that is preventing the switch to finish.
>
>
>
>>
>>
>> ams at ams-repl2.ams.netmgmt:~$ /a/third-party/postgresql/bin/psql -U
>> ams_slony -d ams -c 'select * from _ams_cluster.sl_status'
>>   st_origin | st_received | st_last_event |       st_last_event_ts
>>  |
>> st_last_received |      st_last_received_ts      |
>> st_last_received_event_ts   | st_lag_num_events |   st_lag_time
>> 
>>-----------+-------------+---------------+-------------------------------
>>+-
>> 
>>-----------------+-------------------------------+-----------------------
>>--
>> ------+-------------------+-----------------
>>           2 |           1 |    5000611610 | 2016-01-28
>>16:06:37.343826+00 |
>>        5000611610 | 2016-01-28 16:06:38.843562+00 | 2016-01-28
>> 16:06:37.343826+00 |                 0 | 00:00:09.201996
>>           2 |           3 |    5000611610 | 2016-01-28
>>16:06:37.343826+00 |
>>        5000611609 | 2016-01-28 16:06:29.851545+00 | 2016-01-28
>> 16:06:27.341894+00 |                 1 | 00:00:19.203928
>>           2 |           4 |    5000611610 | 2016-01-28
>>16:06:37.343826+00 |
>>        5000611610 | 2016-01-28 16:06:38.710974+00 | 2016-01-28
>> 16:06:37.343826+00 |                 0 | 00:00:09.201996
>> (3 rows)
>>
>>
>> ams at ams-repl3.lga.netmgmt:~$  /a/third-party/postgresql/bin/psql -U
>> ams_slony -d ams -c 'select * from _ams_cluster.sl_status'
>>   st_origin | st_received | st_last_event |       st_last_event_ts
>>  |
>> st_last_received |      st_last_received_ts      |
>> st_last_received_event_ts   | st_lag_num_events |   st_lag_time
>> 
>>-----------+-------------+---------------+-------------------------------
>>+-
>> 
>>-----------------+-------------------------------+-----------------------
>>--
>> ------+-------------------+-----------------
>>           3 |           4 |    5000654642 | 2016-01-28
>>16:07:05.493455+00 |
>>        5000654642 | 2016-01-28 16:07:06.486539+00 | 2016-01-28
>> 16:07:05.493455+00 |                 0 | 00:00:08.522529
>>           3 |           1 |    5000654642 | 2016-01-28
>>16:07:05.493455+00 |
>>        5000654642 | 2016-01-28 16:07:08.040292+00 | 2016-01-28
>> 16:07:05.493455+00 |                 0 | 00:00:08.522529
>>           3 |           2 |    5000654642 | 2016-01-28
>>16:07:05.493455+00 |
>>        5000654642 | 2016-01-28 16:07:08.472049+00 | 2016-01-28
>> 16:07:05.493455+00 |                 0 | 00:00:08.522529
>> (3 rows)
>>
>>
>> ams at ams-repl4.blr.netmgmt:~$  /a/third-party/postgresql/bin/psql -U
>> ams_slony -d ams -c 'select * from _ams_cluster.sl_status'
>>   st_origin | st_received | st_last_event |       st_last_event_ts
>>  |
>> st_last_received |      st_last_received_ts      |
>> st_last_received_event_ts   | st_lag_num_events |   st_lag_time
>> 
>>-----------+-------------+---------------+-------------------------------
>>+-
>> 
>>-----------------+-------------------------------+-----------------------
>>--
>> ------+-------------------+-----------------
>>           4 |           3 |    5000637483 | 2016-01-28
>>16:07:32.698809+00 |
>>        5000637482 | 2016-01-28 16:07:28.731404+00 | 2016-01-28
>> 16:07:22.695826+00 |                 1 | 00:00:19.077657
>>           4 |           1 |    5000637483 | 2016-01-28
>>16:07:32.698809+00 |
>>        5000637482 | 2016-01-28 16:07:24.839978+00 | 2016-01-28
>> 16:07:22.695826+00 |                 1 | 00:00:19.077657
>>           4 |           2 |    5000637483 | 2016-01-28
>>16:07:32.698809+00 |
>>        5000637482 | 2016-01-28 16:07:22.926411+00 | 2016-01-28
>> 16:07:22.695826+00 |                 1 | 00:00:19.077657
>> (3 rows)
>>
>>
>>
>> 	Tom    :-)
>>
>>
>>
>> On 1/28/16, 10:38 AM, "Jan Wieck" <jan at wi3ck.info> wrote:
>>
>>>On 01/28/2016 08:30 AM, Tignor, Tom wrote:
>>>>
>>>> Hello slony folks,
>>>>  From my reading I¹m guessing (hoping) this isn¹t a new problem. I
>>>>have
>>>> a simple cluster with one provider replicating to three subscribers.
>>>>The
>>>> provider¹s changelog tables (sl_log_[1|2]) are fine, but the
>>>>subscribers
>>>> (with forwarding enabled) are all showing runaway growth. Looked
>>>>through
>>>> the FAQ and I don¹t see the node I dropped or any idle transactions as
>>>> viable culprits. Are there other thoughts on the cause? Can I safely
>>>> manually delete/truncate some/all of the changelog tables? These
>>>> replicas are all leaf nodes. I only have forwarding turned on to allow
>>>> for failover, and my replication rate is the 2 sec default.
>>>> Thanks in advance for any insights.
>>>
>>>What is the output of the sl_status view "on those leaf nodes"?
>>>
>>>
>>>>
>>>> ams=# select
>>>> pg_size_pretty(pg_total_relation_size('_ams_cluster.sl_log_1'));
>>>>
>>>>   pg_size_pretty
>>>>
>>>> ----------------
>>>>
>>>>   75 MB
>>>>
>>>> (1 row)
>>>>
>>>>
>>>> ams=# select
>>>> pg_size_pretty(pg_total_relation_size('_ams_cluster.sl_log_2'));
>>>>
>>>>   pg_size_pretty
>>>>
>>>> ----------------
>>>>
>>>>   34 GB
>>>>
>>>> (1 row)
>>>>
>>>>
>>>> ams=# select * from _ams_cluster.sl_confirm where con_origin not in
>>>> (select no_id from _ams_cluster.sl_node) or con_received not in
>>>>(select
>>>> no_id from _ams_cluster.sl_node);
>>>>
>>>>   con_origin | con_received | con_seqno | con_timestamp
>>>>
>>>> ------------+--------------+-----------+---------------
>>>>
>>>> (0 rows)
>>>>
>>>>
>>>> ams=# select * from pg_stat_activity where current_query like
>>>>'%IDLE%';
>>>>
>>>>   datid | datname | procpid | usesysid |  usename   |
>>>> application_name      |  client_addr   | client_hostname |
>>>>client_port |
>>>>          backend_start         |          xact_start           |
>>>>    query_start          | waiting |
>>>>
>>>>                          current_query
>>>>
>>>>
>>>>-------+---------+---------+----------+------------+-------------------
>>>>--
>>>>------+----------------+-----------------+-------------+---------------
>>>>--
>>>>--------------+-------------------------------+------------------------
>>>>--
>>>>-----+---------+---
>>>>
>>>> ----------------------------------------------------------------
>>>>
>>>>   16393 | ams     |    2611 |   212995 | ams_viewer |
>>>>          | 88.221.209.10  |                 |       43328 | 2016-01-28
>>>> 12:24:49.706389+00 |                               | 2016-01-28
>>>> 13:18:02.427848+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |   12894 |   212995 | ams_viewer |
>>>>          | 88.221.209.10  |                 |       60112 | 2016-01-28
>>>> 12:47:26.230681+00 |                               | 2016-01-28
>>>> 13:15:27.744242+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |   12884 |   212995 | ams_viewer |
>>>>          | 88.221.209.10  |                 |       44302 | 2016-01-28
>>>> 12:47:25.100006+00 |                               | 2016-01-28
>>>> 13:15:27.936059+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |   23466 |   213867 | ams_slony  | psql
>>>>          |                |                 |          -1 | 2016-01-28
>>>> 13:11:32.030343+00 | 2016-01-28 13:18:37.283992+00 | 2016-01-28
>>>> 13:18:37.283992+00 | f       | se
>>>>
>>>> lect * from pg_stat_activity where current_query like '%IDLE%';
>>>>
>>>>   16393 | ams     |    6719 |   213867 | ams_slony  |
>>>> slon.origin_2_provider_2  | 60.254.150.133 |                 |
>>>> 61806 | 2016-01-22 01:59:14.800129+00 |
>>>>|
>>>> 2016-01-28 13:18:25.935111+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    6718 |   213867 | ams_slony  |
>>>> slon.origin_3_provider_2  | 60.254.150.133 |                 |
>>>> 61805 | 2016-01-22 01:59:14.797655+00 |
>>>>|
>>>> 2016-01-28 13:18:34.304475+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    5505 |   213867 | ams_slony  |
>>>> slon.origin_4_provider_2  | 80.67.75.105   |                 |
>>>> 36477 | 2016-01-22 01:56:25.637046+00 |
>>>>|
>>>> 2016-01-28 13:18:36.1348+00   | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    5504 |   213867 | ams_slony  |
>>>> slon.origin_3_provider_2  | 72.246.50.22   |                 |
>>>> 51813 | 2016-01-22 01:56:25.240798+00 |
>>>>|
>>>> 2016-01-28 13:18:28.961629+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    5487 |   213867 | ams_slony  |
>>>> slon.origin_4_provider_2  | 72.246.50.22   |                 |
>>>> 51803 | 2016-01-22 01:56:22.896388+00 |
>>>>|
>>>> 2016-01-28 13:18:35.858913+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    5047 |   213867 | ams_slony  |
>>>> slon.origin_2_provider_2  | 72.246.50.22   |                 |
>>>> 51564 | 2016-01-22 01:55:23.600296+00 |
>>>>|
>>>> 2016-01-28 13:18:34.487192+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    5041 |   213867 | ams_slony  |
>>>> slon.origin_2_provider_2  | 80.67.75.105   |                 |
>>>> 36402 | 2016-01-22 01:55:22.964462+00 |
>>>>|
>>>> 2016-01-28 13:18:34.519066+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    6694 |   213867 | ams_slony  |
>>>> slon.node_2_listen        | 60.254.150.133 |                 |
>>>> 61795 | 2016-01-22 01:59:12.095052+00 |
>>>>|
>>>> 2016-01-28 13:18:27.928384+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4456 |   213867 | ams_slony  |
>>>> slon.node_2_listen        | 72.246.50.22   |                 |
>>>> 51238 | 2016-01-22 01:54:21.481355+00 |
>>>>|
>>>> 2016-01-28 13:18:36.766973+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4457 |   213867 | ams_slony  |
>>>> slon.node_2_listen        | 80.67.75.105   |                 |
>>>> 36333 | 2016-01-22 01:54:21.500456+00 |
>>>>|
>>>> 2016-01-28 13:18:36.204482+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4428 |   213867 | ams_slony  |
>>>> slon.local_monitor        |                |                 |
>>>> -1 | 2016-01-22 01:54:18.977015+00 |                               |
>>>> 2016-01-28 13:18:36.652567+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4427 |   213867 | ams_slony  | slon.local_sync
>>>>          |                |                 |          -1 | 2016-01-22
>>>> 01:54:18.976932+00 |                               | 2016-01-28
>>>> 13:18:36.151998+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4426 |   213867 | ams_slony  |
>>>> slon.local_cleanup        |                |                 |
>>>> -1 | 2016-01-22 01:54:18.976842+00 |                               |
>>>> 2016-01-28 13:12:12.582921+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4425 |   213867 | ams_slony  |
>>>> slon.remoteWorkerThread_4 |                |                 |
>>>> -1 | 2016-01-22 01:54:18.976783+00 |                               |
>>>> 2016-01-28 13:18:33.99715+00  | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4420 |   213867 | ams_slony  |
>>>> slon.remoteWorkerThread_1 |                |                 |
>>>> -1 | 2016-01-22 01:54:18.976548+00 |                               |
>>>> 2016-01-28 13:18:33.561531+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4419 |   213867 | ams_slony  |
>>>> slon.remoteWorkerThread_3 |                |                 |
>>>> -1 | 2016-01-22 01:54:18.97647+00  |                               |
>>>> 2016-01-28 13:18:34.808907+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>>   16393 | ams     |    4413 |   213867 | ams_slony  |
>>>>slon.local_listen
>>>>          |                |                 |          -1 | 2016-01-22
>>>> 01:54:18.965568+00 |                               | 2016-01-28
>>>> 13:18:37.096159+00 | f       | <I
>>>>
>>>> DLE>
>>>>
>>>> (21 rows)
>>>>
>>>>
>>>> ams=#
>>>>
>>>>
>>>>
>>>> Tom    :-)
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Slony1-general mailing list
>>>> Slony1-general at lists.slony.info
>>>> http://lists.slony.info/mailman/listinfo/slony1-general
>>>>
>>>
>>>
>>>--
>>>Jan Wieck
>>>Senior Software Engineer
>>>http://slony.info
>>
>
>
>-- 
>Jan Wieck
>Senior Software Engineer
>http://slony.info



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