Re: BUG #15078: Unable to receive data from WAL Stream Error

On 02/22/2018 07:43 PM, Kolla, Mahesh wrote:
> Hello Tom ,
> 
> Please let me know why we are getting below associated LOGS saying
invalid resource manager with the FATAL message Unable to receive data
from WAL Stream Error
> 
>> sh: dev/null: No such file or directory
>> sh: dev/null: No such file or directory < 2018-02-19 01:37:48.860 CST 
>>> LOG:  invalid resource manager ID 48 at
>> 15/2D69E848
> 

I believe that essentially means the WAL is corrupted in some way,
possibly due to a network issue. I don't think I've seen such error
message though, so not sure.

FWIW  it's really hard to investigate issues when you only copy three
lines, two of which are errors in your shell script. That provides no
context whatsoever.

> Please kindly suggest us a value for tcp_keepalives_idle as it is
> presently set to 0
> 

That really depends on your networking configuration, but you can try this:

tcp_keepalives_idle = 60
tcp_keepalives_interval = 15
tcp_keepalives_count = 3

which essentially pings the server every 60 seconds, if the server does
not respond in 15 seconds it'll try again, and will consider the
connection gone after 3 failures.

But it's unclear if this really is a networking issue, so hard to say if
this improves the situation.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services