Re: Streaming replication - 11.5

On 3/16/20 2:57 AM, Nicola Contu wrote:
> I was able to make pg_basebackup working using --max-rate=128M
>
> Still don't understand why. I guess it is related to the encryption and
> slowness of the disk..
> Do you have any idea?

I think your explanation fits. Encryption/decryption have overhead.

>
> Il giorno ven 13 mar 2020 alle ore 16:15 Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>> ha scritto:
>
> On 3/13/20 4:11 AM, Nicola Contu wrote:
> > So in the logs I now see this :
> >
> > 2020-03-13 11:03:42 GMT [10.150.20.22(45294)] [27804]: [1-1]
> > db=[unknown],user=replicator LOG:  terminating walsender process
> due to
> > replication timeout
>
> Yeah that's been showing up the log snippets you have been posting.
>
> To figure this out you will need to:
>
> 1) Make a list of what changed since the last time replication worked
> consistently.
>
> 2) Monitor the changed components, start logging or increase logging.
>
> 3) Monitor the chain of replication as whole, to catch changes that you
> do not know about. Since you seem to be operating across data centers
> that would include verifying the network.
>
> >
> > So I tried increasing the wal_sender_timeout to 300s but it did
> not help
> >
> > Il giorno gio 12 mar 2020 alle ore 15:56 Nicola Contu
> > <nicola(dot)contu(at)gmail(dot)com <mailto:nicola(dot)contu(at)gmail(dot)com>
> <mailto:nicola(dot)contu(at)gmail(dot)com <mailto:nicola(dot)contu(at)gmail(dot)com>>> ha
> scritto:
> >
> >     The encryption is at os level. So the drives are encrypted with a
> >     password where the db saves data
> >
> >     Il gio 12 mar 2020, 15:51 Adrian Klaver
> <adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> >     <mailto:adrian(dot)klaver(at)aklaver(dot)com
> <mailto:adrian(dot)klaver(at)aklaver(dot)com>>> ha scritto:
> >
> >         On 3/12/20 4:31 AM, Nicola Contu wrote:
> >          > The replicator is ok and the replicated as well.
> >          > %Cpu(s):  0.2 us,  1.0 sy,  0.0 ni, 94.8 id,  4.0 wa,  0.0
> >         hi,  0.0 si,
> >          >   0.0 st
> >          >
> >          > CPU is really low on both.
> >          >
> >          > I am running pg_basebackup again everytime.
> >          > Any other suggestions?
> >          >
> >
> >         I have to believe their is a connection between changing to
> >         encrypting
> >         the disks and your issues. Not sure what, but to help how
> is the
> >         encryption being done and what program is being used?
> >
> >
> >         --
> >         Adrian Klaver
> > adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
> <mailto:adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>>
> >
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com <mailto:adrian(dot)klaver(at)aklaver(dot)com>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com