Re: pg_basebackup and wal streaming

On Sat, Feb 26, 2011 at 20:48, Yeb Havinga <yebhavinga(at)gmail(dot)com> wrote:
> On 2011-02-26 18:19, Magnus Hagander wrote:
>>
>> Attached is an updated version of the patch that includes these
>> changes, as well as Windows support and an initial cut at a ref page
>> for pg_receivexlog (needs some more detail still).
>
> I'm testing a bit more (with the previous version, sorry) and got the
> following while doing a stream backup from a cluster that was at that moment
> doing a pgbench run with 1 synchronous standby.
>
> mgrid(at)mg79:~$ pg_basebackup --xlog=stream -D /data -vP -h mg73 -U repuser
> Password:
> xlog start point: 15/720000C8
> pg_basebackup: starting background WAL receiver
> pg_basebackup: got WAL data offset 14744, expected 16791960424        )
> 5148915/5148026 kb g(100%) 1/1 tablespaces
> xlog end point: 15/80568878
> pg_basebackup: waiting for background process to finish streaming...
> pg_basebackup: child process exited with error 1

Hmm, strange. What platform are you on?

I saw something similar *once* on Windows, but it then passed my tests
a lot of times in a row so I figured it was just a "didn't clean
properly" thing. Clearly there's a bug around.

What's the size of the latest WAL file that it did work on? Is it
16791960424 bytes? That's way way to large, but perhaps it's not
switching segment properly? (that value is supposedly the current
write position in the file..)

> I'm in total monkey test mode here, so I don't even know if I'm not supposed
> to do the streaming variant while other stuff is going on.

Oh yes, that's one of the main reasons to use it, so you should
definitely be able to do that!

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/