Thread: PostgreSQL on Webmin

Kostadin Solakov wrote:
>
> Hi there!
>
> I just installed Webmin on my dedicated server and I really had hard
> time making all configuration that were needed to migrate my site.
> Anyway, now everything is working except for one thing. I can’t
> connect to the database through PHP. Remote connection is working
> fine, but local doesn’t.
>
> The connection string looks like this:
>
> pg_connect('host=localhost port=5432 user=user password=pass dbname=db')
>
> I made the necessary changes in postgresql.conf
>
> listen_addresses = '*'
>
> port=5432
>
> And I added this in pg_nba.conf:
>
> local all all trust
>
> local all user ident sameuser
>
> local db user password
>
> But still I cannot connect using php. The connection file is the same
> as it was on my previous host (shared one) so it’s supposed to be working.
>
> I created the same database and user.
>


the first local all all takes precedence as that matches any local
(domain socket) connections. as is, you're saying any process running
your server can connect to any database as any user with no
authorization required.

however, none of those lines affect localhost IP connections, those
instead would match a `host .... 127.0.0.1/32 ....`



I most typically use the following...

local all all ident sameuser # allow local domain connections to
authenticate only as themselves
host all all 127.0.0.1/32 md5 # allow localhost IP connections to
authenticate with passwords only

and sometimes...

host all all my.ip.sub.net/24 md5 # allow any user on my IP subnet to
authneticate with passwords

Thanks John, I tried that and it works but with some changes I made.
After the changes you suggested I was still getting the same message:
Warning: pg_pconnect() [function.pg-pconnect]: Unable to connect to
PostgreSQL server: could not connect to server: Permission denied Is the
server running on host "localhost" and accepting TCP/IP connections on port
5432?

Anyway I managed to connect to localhost, but after I made changes to
pg_connect and I removed the host name
FROM

   1. pg_pconnect("host=localhost dbname=mydb user=myuser
password=mypassword");

TO

   1. pg_pconnect("dbname=mydb user=myuser password=mypassword");



Now it works, but VERY SLOWER than before.
One of the scripts I'm running on the previous host took below 2 sec for
1000 entries and now it takes 1 sec for 100 entries.

working pg_hba.conf looks like this:

   1. # IPv4 local connections:
   2.  local   all         all                               trust
   3.  local   all         my_user                          ident sameuser
   4.  local my_db my_user password
   5.  host my_db my_user 0.0.0.0/0 password
   6. # IPv6 local connections:
   7.  host    all         all         127.0.0.1/32          ident sameuser
   8.  host    all         all         ::1/128               ident sameuser


-----Original Message-----
From: John R Pierce [mailto:pierce@hogranch.com]
Sent: Monday, March 16, 2009 2:25 AM
To: Kostadin Solakov
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] PostgreSQL on Webmin

Kostadin Solakov wrote:
>
> Hi there!
>
> I just installed Webmin on my dedicated server and I really had hard
> time making all configuration that were needed to migrate my site.
> Anyway, now everything is working except for one thing. I can't
> connect to the database through PHP. Remote connection is working
> fine, but local doesn't.
>
> The connection string looks like this:
>
> pg_connect('host=localhost port=5432 user=user password=pass dbname=db')
>
> I made the necessary changes in postgresql.conf
>
> listen_addresses = '*'
>
> port=5432
>
> And I added this in pg_nba.conf:
>
> local all all trust
>
> local all user ident sameuser
>
> local db user password
>
> But still I cannot connect using php. The connection file is the same
> as it was on my previous host (shared one) so it's supposed to be working.
>
> I created the same database and user.
>


the first local all all takes precedence as that matches any local
(domain socket) connections. as is, you're saying any process running
your server can connect to any database as any user with no
authorization required.

however, none of those lines affect localhost IP connections, those
instead would match a `host .... 127.0.0.1/32 ....`



I most typically use the following...

local all all ident sameuser # allow local domain connections to
authenticate only as themselves
host all all 127.0.0.1/32 md5 # allow localhost IP connections to
authenticate with passwords only

and sometimes...

host all all my.ip.sub.net/24 md5 # allow any user on my IP subnet to
authneticate with passwords

Kostadin Solakov wrote:
> Anyway I managed to connect to localhost, but after I made changes to
> pg_connect and I removed the host name
> FROM
>
>    1. pg_pconnect("host=localhost dbname=mydb user=myuser
> password=mypassword");
>
> TO
>
>    1. pg_pconnect("dbname=mydb user=myuser password=mypassword");
>
>
> Now it works, but VERY SLOWER than before.
> One of the scripts I'm running on the previous host took below 2 sec for
> 1000 entries and now it takes 1 sec for 100 entries.
>

thats odd, as a domain socket should be slightly -faster- than a tcp/ip
socket.   now, since you say 'previous host' I could wonder if other
configuration items are impacting this, such as buffer sizes in
postgresql.conf, relative speed of disk controllers, etc.   or perhaps
this new database hasn't been analyzed since it was populated, or its
indexes need rebuilding, or something similar...


> working pg_hba.conf looks like this:
>
>    1. # IPv4 local connections:
>    2.  local   all         all                               trust
>    3.  local   all         my_user                          ident sameuser
>    4.  local my_db my_user password
>
line 2 masks lines 3,4 as it accepts any connection to any database over
'local' (unix domain socket), so it would never bother to try the others.


>    5.  host my_db my_user 0.0.0.0/0 password
>

that line would allow anyone anywhere (assuming listen_address = '*' in
postgresql.conf, and no firewalls intervene) to connect as myuser to
mydb with a password

John R Pierce wrote:

thats odd, as a domain socket should be slightly -faster- than a tcp/ip
socket.   now, since you say 'previous host' I could wonder if other
configuration items are impacting this, such as buffer sizes in
postgresql.conf, relative speed of disk controllers, etc.   or perhaps
this new database hasn't been analyzed since it was populated, or its
indexes need rebuilding, or something similar...

    I think that is the issue. Previous server was old machine and the
settings in postgresql.conf were the default ones.
    The new machine is Xeon quad with 8GB ram and I already made some
changes in postgresql.conf, but still no result.
    I followed the instructions on
http://www.powerpostgresql.com/PerfList/ and made the following changes:

        shared_buffers = 50000
        work_mem = 512000
        checkpoint_segments = 32
        effective_cache_size = 200000

    Also I ran REINDEX on the DB and VACUUM VERBOSE ANALYZE on each
table, but still the results are the same as before.
    What are the settings you recommend for this server?
    The application that is going to use it has a very demanding back
end, it parses very large XML files (20+) and saves the data in the DB.

    Thanks, Kosta

On Monday 16 March 2009 17:55:00 Kostadin Solakov wrote:
> John R Pierce wrote:
>
> thats odd, as a domain socket should be slightly -faster- than a tcp/ip
> socket.   now, since you say 'previous host' I could wonder if other
> configuration items are impacting this, such as buffer sizes in
> postgresql.conf, relative speed of disk controllers, etc.   or perhaps
> this new database hasn't been analyzed since it was populated, or its
> indexes need rebuilding, or something similar...
>
>     I think that is the issue. Previous server was old machine and the
> settings in postgresql.conf were the default ones.
>     The new machine is Xeon quad with 8GB ram and I already made some
> changes in postgresql.conf, but still no result.
>     I followed the instructions on
> http://www.powerpostgresql.com/PerfList/ and made the following changes:
>
>         shared_buffers = 50000
>         work_mem = 512000
>         checkpoint_segments = 32
>         effective_cache_size = 200000
>
>     Also I ran REINDEX on the DB and VACUUM VERBOSE ANALYZE on each
> table, but still the results are the same as before.
>     What are the settings you recommend for this server?
>     The application that is going to use it has a very demanding back
> end, it parses very large XML files (20+) and saves the data in the DB.
>

Unless you're actually running 8.2, that information is a bit out of date.
There's a better write up at
http://wiki.postgresql.org/wiki/Tuning_Your_PostgreSQL_Server

Once you go through that and restart, if it's still slow, can you paste
explain analyze from the two different servers?

--
Robert Treat
Conjecture: http://www.xzilla.net
Consulting: http://www.omniti.com