22 Sep
2009
22 Sep
'09
9:28 a.m.
Hi *,
What would be the suggestions regarding having a process / thread that can
be used to ping (keepalive) a connection to a particular db backend. I am
specifically looking at coding something for mysql (our firewall is closing
connections to mysql if they are idle for longer than 30mins). I would like
to have a process that would go through all connections and "ping" them
every so often. I would imagine each DB impl can either ignore the ping
function or actually do something with it. I would imagine this will be
useful for a few backend db implementations. Any input before I go ahead?
Cheers
Jason
22 Sep
22 Sep
9:38 a.m.
On Sep 22, 2009 at 09:28, Jason Penton <jason.penton(a)smilecoms.com> wrote:
Hi *,
What would be the suggestions regarding having a process / thread that can
be used to ping (keepalive) a connection to a particular db backend. I am
specifically looking at coding something for mysql (our firewall is closing
connections to mysql if they are idle for longer than 30mins). I would like
to have a process that would go through all connections and "ping" them
every so often. I would imagine each DB impl can either ignore the ping
function or actually do something with it. I would imagine this will be
useful for a few backend db implementations. Any input before I go ahead?
Doesn't modparam("db_mysql", "ping_interval", 15) work?
Andrei
9:43 a.m.
Hi Andrei,
From what I have seen in the code this is pretty
useless (no offence).
The ping in this particular instance is only executed JUST before a real
query is to be issued. i.e. if a query is not used in Kamailio for a couple
of hours - the ping is actually never sent...........
what I have noticed is that when the connection is torn down by the
firewall, the ping actually hangs (reconnect fails), etc
So, we NEED a proper ping (keepalive) functionality :D
Cheers
Jason
On Tue, Sep 22, 2009 at 9:38 AM, Andrei Pelinescu-Onciul
<andrei(a)iptel.org>wrote;wrote:
On Sep 22, 2009 at 09:28, Jason Penton
<jason.penton(a)smilecoms.com> wrote:
Hi *,
What would be the suggestions regarding having a process / thread that
can
be used to ping (keepalive) a connection to a
particular db backend. I am
specifically looking at coding something for mysql (our firewall is
closing
connections to mysql if they are idle for longer
than 30mins). I would
like
to have a process that would go through all
connections and "ping" them
every so often. I would imagine each DB impl can either ignore the ping
function or actually do something with it. I would imagine this will be
useful for a few backend db implementations. Any input before I go ahead?
Doesn't modparam("db_mysql", "ping_interval", 15) work?
Andrei
12:46 p.m.
On Dienstag, 22. September 2009, Jason Penton wrote:
Hi Andrei,
From what I have seen in the code this is pretty useless (no offence).
The ping in this particular instance is only executed JUST before a real
query is to be issued. i.e. if a query is not used in Kamailio for a couple
of hours - the ping is actually never sent...........
Hi Jason,
you're right that its not executed with a timer or similar, but the
mysql_ping() should reconnect to the database if the auto reconnect is
activated, according the documentation:
http://dev.mysql.com/doc/refman/5.0/en/mysql-ping.html
what I have noticed is that when the connection is
torn down by the
firewall, the ping actually hangs (reconnect fails), etc
So, we NEED a proper ping (keepalive) functionality :D
This could be implemented with help of the internal timers, just execute
periodically the mysql_ping command, for example.
Henning
12:50 p.m.
Hello,
On 22.09.2009 12:46 Uhr, Henning Westerholt wrote:
On Dienstag, 22. September 2009, Jason Penton wrote:
what are you referring as "internal timer" -- the connections are per
process, not shared across them, therefore the ping has to be sent from
same process.
Cheers,
Daniel
--
Daniel-Constantin Mierla
* http://www.asipto.com/
Hi Andrei,
From what I have seen in the code this is pretty useless (no offence).
The ping in this particular instance is only executed JUST before a real
query is to be issued. i.e. if a query is not used in Kamailio for a
couple
of hours - the ping is actually never
sent...........
Hi Jason,
you're right that its not executed with a timer or similar, but the
mysql_ping() should reconnect to the database if the auto reconnect is
activated, according the documentation:
http://dev.mysql.com/doc/refman/5.0/en/mysql-ping.html
what I have noticed is that when the connection
is torn down by the
firewall, the ping actually hangs (reconnect fails), etc
So, we NEED a proper ping (keepalive) functionality :D
This could be implemented with help of the internal timers, just
execute periodically the mysql_ping command, for example.
12:55 p.m.
Hey Henning,
On Tue, Sep 22, 2009 at 12:46 PM, Henning Westerholt <
henning.westerholt(a)1und1.de> wrote:
On Dienstag, 22. September 2009, Jason Penton wrote:
Actually the reconnect doesnt work if your firewall has torn down the
connection. You can try this with other mysql clients like - the usual
client, toad, etc. Leave your connection idle for about 45 mins and you will
see that there's nothing you can do to reconnect.
I have tested this extensively and can only imageine that because the
firewall has closed the connection, the reconnect in mysql doesnt work -
because the socket has been torn down underneath mysql (at the OS level). So
effectively you see a hangin process in Kamailio up to 5 minutes :) which is
REALLLLLLLLY bad :D
Ok so I am going to go ahead with using a timer to ping the mysql cons in
the db_pool. Everyone happy with that?
Cheers
Jason
Hi Andrei,
From what I have seen in the code this is pretty useless (no offence).
The ping in this particular instance is only executed JUST before a real
query is to be issued. i.e. if a query is not used in Kamailio for a
couple
of hours - the ping is actually never
sent...........
Hi Jason,
you're right that its not executed with a timer or similar, but the
mysql_ping() should reconnect to the database if the auto reconnect is
activated, according the documentation:
http://dev.mysql.com/doc/refman/5.0/en/mysql-ping.html
what I have noticed is that when the connection
is torn down by the
firewall, the ping actually hangs (reconnect fails), etc
So, we NEED a proper ping (keepalive) functionality :D
This could be implemented with help of the internal timers, just execute
periodically the mysql_ping command, for example.
Henning
1:15 p.m.
On Dienstag, 22. September 2009, Jason Penton wrote:
Hi Jason,
ok, i'd just re-configure the firewall to not be stateful anymore, this is
easier as working around in the application IMHO. But perhaps this is not
possible in your case.
you're
right that its not executed with a timer or similar, but the
mysql_ping() should reconnect to the database if the auto reconnect is
activated, according the documentation:
http://dev.mysql.com/doc/refman/5.0/en/mysql-ping.html
Actually the reconnect doesnt work if your firewall has torn down the
connection. You can try this with other mysql clients like - the usual
client, toad, etc. Leave your connection idle for about 45 mins and you
will see that there's nothing you can do to reconnect. I have tested this extensively and can only imageine
that because the
firewall has closed the connection, the reconnect in mysql doesnt work -
because the socket has been torn down underneath mysql (at the OS level).
So effectively you see a hangin process in Kamailio up to 5 minutes :)
which is REALLLLLLLLY bad :D
This is strange, do you've tried to set the timeout_interval parameter? We do
regularly tests where we block on network level all connections to the mysql,
and it notices this and reports an error to the upper level. Perhaps the mysql
version you use not supports this parameter? You find in the mod docs the
versions.
Ok so I am going to go ahead with using a timer to
ping the mysql cons in
the db_pool. Everyone happy with that?
As Daniel already mentioned, you need to ping from the individual process and
not the timer process, otherwise it probably will not work.
Regards,
Henning
2:20 p.m.
Jason Penton schrieb:
I have tested this extensively and can only imageine
that because the
firewall has closed the connection, the reconnect in mysql doesnt work -
because the socket has been torn down underneath mysql (at the OS
level). So effectively you see a hangin process in Kamailio up to 5
minutes :) which is REALLLLLLLLY bad :D
If the problem is in the mysql client library, it should be fixed there.
Pinging can reduce the problem, but what happens if the TCP connection
is lost during the ping intervals? Will the pinging hang for 5 minutes?
regards
klaus
23 Sep
23 Sep
3:59 a.m.
On Tue, Sep 22, 2009 at 12:55 PM, Jason Penton
<jason.penton(a)smilecoms.com> wrote:
Hey Henning,
On Tue, Sep 22, 2009 at 12:46 PM, Henning Westerholt
<henning.westerholt(a)1und1.de> wrote:
I am not sure I understand. The reconnect option in mysql should be
able to recover from this. It can reconnect even if you restart the
database server. The client library does not really care about the
reason why the connection was lost.
One reason why you might be seeing the long interval is because the
client does not know that the firewall shut the connection down. It
tries to send TCP segments on that connection but they are discarded
by the firewall. In that case it takes time until the socket layer
notifies the mysqlclient library that the connection was lost.
On Dienstag, 22. September 2009, Jason Penton wrote:
Actually the reconnect doesnt work if your firewall has torn down the
connection. You can try this with other mysql clients like - the usual
client, toad, etc. Leave your connection idle for about 45 mins and you will
see that there's nothing you can do to reconnect.
I have tested this extensively and can only imageine that because the
firewall has closed the connection, the reconnect in mysql doesnt work -
because the socket has been torn down underneath mysql (at the OS level). So
effectively you see a hangin process in Kamailio up to 5 minutes :) which is
REALLLLLLLLY bad :D Hi Andrei,
From what I have seen in the code this is pretty useless (no offence).
The ping in this particular instance is only executed JUST before a real
query is to be issued. i.e. if a query is not used in Kamailio for a
couple
of hours - the ping is actually never sent...........
Hi Jason,
you're right that its not executed with a timer or similar, but the
mysql_ping() should reconnect to the database if the auto reconnect is
activated, according the documentation:
http://dev.mysql.com/doc/refman/5.0/en/mysql-ping.html Ok so I am going to go ahead with using a timer to
ping the mysql cons in
the db_pool. Everyone happy with that?
It probably won't work this way, because you cannot ping all
connections from one process. Every ser/kamailio process opens its own
connection to the database and if you want to send a ping on a
connection, you have to do it in the process which created the
connection.
But that is difficult because most processes are normally suspended in
recvfrom if they do not have a SIP message to process.
Jan.
5350
days inactive
5351
days old
8 comments
6 participants
participants (6)
-
Andrei Pelinescu-Onciul -
Daniel-Constantin Mierla -
Henning Westerholt -
Jan Janak -
Jason Penton -
Klaus Darilion