On 12/10/2009 9:01 AM, Devrim GÜNDÜZ wrote:
> Hi,
> 
> I have a slon instance that is running 2.0.3 RC3 with PostgreSQL 8.3 and
> 8.4. They all run on the same server (my personal server).
> 
> Today I restarted 8.3 instance to perform an upgrade. Since then,
> Slony-I reports a lag when I query it from slave. On master, everything
> looks ok. There is nothing suspicious in the logs -- and logs say that
> data is flowing from 8.3 to 8.4 -- and I confirmed that data on origin
> and subscriber are the same.
> 
> I restarted slon daemons, but it did not help. It just reset the lag
> time, but since then lag is still increasing.
> 
> Here is what I exactly have:
> 
> Origin:
> 
> # SELECT * from _replication.sl_status;
> -[ RECORD 1 ]-------------+---------------------------
> st_origin                 | 3
> st_received               | 4
> st_last_event             | 902839
> st_last_event_ts          | 2009-12-10 16:02:56.016067
> st_last_received          | 902838
> st_last_received_ts       | 2009-12-10 16:02:51.185257
> st_last_received_event_ts | 2009-12-10 16:02:46.011313
> st_lag_num_events         | 1
> st_lag_time               | 00:00:13.556469
> 
> Subscriber:
> 
> # SELECT * from _replication.sl_status;
> -[ RECORD 1 ]-------------+---------------------------
> st_origin                 | 4
> st_received               | 3
> st_last_event             | 19
> st_last_event_ts          | 2009-12-10 15:59:58.911679
> st_last_received          | 19
> st_last_received_ts       | 2009-12-10 16:00:01.781158
> st_last_received_event_ts | 2009-12-10 15:59:58.911679
> st_lag_num_events         | 0
> st_lag_time               | 00:03:38.107517
> 
> 
> Is there anything that I can help you to debug this issue? 

What issue? The last event created by the node is 19, which is confirmed 
by the other node. That happened some time ago, but there is nothing 
fundamentally wrong here. Slony only generates SYNC events when there is 
replication data to transport, and every now and then one for good 
measure (I forgot what the default interval is for that). You can play 
with the -t option if you don't like to see that lag.


Jan

-- 
Anyone who trades liberty for security deserves neither
liberty nor security. -- Benjamin Franklin