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cisaksen
07-Mar-2014, 19:45
I'm trying to determine if I have a tcp connections issue and I'm looking for any information on what the default tcp connections are and how they can be tuned for say mysql.

The issue I am dealing with is I'm running 17 instances of mysql on a single server. There desn't appear to be a problem with this other than the fact that I have a large amount of time_waits in netstat. Here is a small sample of what they look like:

tcp 0 0 127.0.0.1:3306 127.0.0.1:47441 TIME_WAIT
tcp 0 0 127.0.0.1:47092 127.0.0.1:3315 TIME_WAIT
tcp 0 0 127.0.0.1:46813 127.0.0.1:3317 TIME_WAIT
tcp 0 0 127.0.0.1:3306 127.0.0.1:46659 TIME_WAIT
tcp 0 0 127.0.0.1:41084 127.0.0.1:3312 TIME_WAIT
tcp 0 0 127.0.0.1:49826 127.0.0.1:3321 TIME_WAIT
tcp 0 0 127.0.0.1:38991 127.0.0.1:3314 TIME_WAIT
tcp 0 0 127.0.0.1:38876 127.0.0.1:3314 TIME_WAIT


Someone suggested that mysql may not be getting enough tcp connections. I haven't change the default of 151 connection for mysql (5.6).

Any information would be helpful.

thank you

malcolmlewis
07-Mar-2014, 20:13
On Fri 07 Mar 2014 06:54:02 PM CST, cisaksen wrote:


I'm trying to determine if I have a tcp connections issue and I'm
looking for any information on what the default tcp connections are and
how they can be tuned for say mysql.

The issue I am dealing with is I'm running 17 instances of mysql on a
single server. There desn't appear to be a problem with this other than
the fact that I have a large amount of time_waits in netstat. Here is a
small sample of what they look like:

tcp 0 0 127.0.0.1:3306 127.0.0.1:47441
TIME_WAIT
tcp 0 0 127.0.0.1:47092 127.0.0.1:3315
TIME_WAIT
tcp 0 0 127.0.0.1:46813 127.0.0.1:3317
TIME_WAIT
tcp 0 0 127.0.0.1:3306 127.0.0.1:46659
TIME_WAIT
tcp 0 0 127.0.0.1:41084 127.0.0.1:3312
TIME_WAIT
tcp 0 0 127.0.0.1:49826 127.0.0.1:3321
TIME_WAIT
tcp 0 0 127.0.0.1:38991 127.0.0.1:3314
TIME_WAIT
tcp 0 0 127.0.0.1:38876 127.0.0.1:3314
TIME_WAIT


Someone suggested that mysql may not be getting enough tcp connections.
I haven't change the default of 151 connection for mysql (5.6).

Any information would be helpful.

thank you




Hi
This is normal, because TIME_WAIT means the connection has been
closed and it's just waiting to make sure there are no stray packets
before it really closes.

So maybe it's a red-herring so to speak?

--
Cheers Malcolm °¿° SUSE Knowledge Partner (Linux Counter #276890)
openSUSE 13.1 (Bottle) (x86_64) GNOME 3.10.2 Kernel 3.11.10-7-desktop
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