Replication eRServer problems
I just implemented eRServer for one of my clients and found many problems
with it.
1. It crashes when using �ers_addtable� to add big tables. The problem is
that it used pg_dump �d then tried to read the whole output in memory. I
fixed it by reading one row at a time and inserting it to slave.
2. �ers_addslave� crashes when creating table schema if one rows on the
master were dropped. Apparently, when a row was dropped, the �attname� in
�pg_attribute� table was changed to ����pg.dropped.#����..� and the type of
the column became �-�. That made the �create table� sql statement for slave
wrong. I fixed this problem by excluding those kind of columns.
3. There was no index created on �_ers_uniq� on slave side. It took minutes
per transaction to delete on huge tables. After I found the problem and
created index on the column, it only took about 5 milliseconds to delete.
4. To handle columns with default and nextval, eRServer expected to see
nextval('"sequence_name"'::text) and used double quote to extract sequence
names. But postgres also allow nextval('sequence_name'::text) without double
quotes. The fix was easy.
5. eRServer.pm failed because DBI could not handle columns with types such
as �text[]� but Pg module should work.
Hope those will be fixed in the next version. I can also provide my fixes if
needed.
John Li
John Li wrote:
I just implemented eRServer for one of my clients and found many
problems with it.
We do not maintain erserver. You need to talk to the people that you
got it from, for example here:
http://gborg.postgresql.org/project/erserver/projdisplay.php
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Hi,
On Mon, 16 Feb 2004, John Li wrote:
I just implemented eRServer for one of my clients and found many problems
with it.
TDMSoft has patched eRServer a bit:
http://www.tdmsoft.com/tr/PostgreSQL/download/
Maybe these could help to solve your problems.
Regards,
- --
Devrim GUNDUZ
devrim@gunduz.org devrim.gunduz@linux.org.tr
http://www.TDMSoft.com
http://www.gunduz.org
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On Mon, Feb 16, 2004 at 10:16:39AM -0800, John Li wrote:
I just implemented eRServer for one of my clients and found many problems
with it.
Yep. There's a list dedicated to it, by the way, available through
the gborg site.
1. It crashes when using ?ers_addtable? to add big tables. The problem is
that it used pg_dump ?d then tried to read the whole output in memory. I
fixed it by reading one row at a time and inserting it to slave.
The setup scripts are pretty buggy.
3. There was no index created on ?_ers_uniq? on slave side. It took minutes
per transaction to delete on huge tables. After I found the problem and
created index on the column, it only took about 5 milliseconds to delete.
This is a new report. Thanks.
Hope those will be fixed in the next version. I can also provide my fixes if
needed.
I'm interested in seeing patches, for sure. I'll be applying some
things this weekend, so I'll test for the cases you mention and hit
you up for patches once I'm done.
A
--
Andrew Sullivan | ajs@crankycanuck.ca
This work was visionary and imaginative, and goes to show that visionary
and imaginative work need not end up well.
--Dennis Ritchie