NETTYPE maximum support to user connections ?
Asked what the maximum number of TCP connections NETTYPE tlitcp,8,50,NET allows. Replies explained NETTYPE doesn't cap connections — it just sets dedicated poll/listener resources, and the server allocates more on the fly; for efficiency, keep roughly 350–500 connections per listener (so 8 listeners handle ~2800–4000 users). The poster then reported listener-thread error -25571 "Cannot create a user thread" blocking all connections. Suggestions were to check LIMITNUMSESSIONS, the obsolete USERTHREADS parameter, OS resource limits/system message logs, and the finderr -25571 text. The poster said neither parameter was set; no resolution is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Lets consider the following value of NETTYPE parameter.
NETTYPE tlitcp,8,50,NET
What is the maximum number of tcp connections this parameter can support with
this value?
What would happen when the maximum allowed limit (derived through these param
value) would reach ?
Anees
All connection types are dynamic except shared memory connections. They
will automatically increase. However, for efficiency, you don't want more
than about 350-500 connections per listener, so your eight listeners
together can handle fro 2800 to 4000 users efficiently.
Art
Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on my employer, Advanced DataTools, the IIUG, nor any
other organization with which I am associated either explicitly,
implicitly, or by inference. Neither do those opinions reflect those of
other individuals affiliated with any entity with which I am affiliated nor
those of the entities themselves.
On Tue, Jun 19, 2012 at 7:19 AM, ANEES AHMAD <aanees@i2cinc.com> wrote:
> Lets consider the following value of NETTYPE parameter.
>
> NETTYPE tlitcp,8,50,NET>
> What is the maximum number of tcp connections this parameter can support
> with
> this value?
>
> What would happen when the maximum allowed limit (derived through these
> param
> value) would reach ?
>
> Anees
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--90e6ba61487063951604c2d18753
The NETTYPE parameter does NOT limit the number of tcp connections. I=
t
just instructs the informix server on the number of resources you would=
like to dedicate to service the tcp connections. If more resources are=
required then the server will allocate these resources on the fly.
John F. Miller III
STSM, Embedability Architect
miller3@us.ibm.com
503-578-5645
IBM Informix Dynamic Server (IDS)
ids-bounces@iiug.org wrote on 06/19/2012 04:19:47 AM:
> From: "ANEES AHMAD" <aanees@i2cinc.com>
> To: ids@iiug.org,
> Date: 06/19/2012 04:20 AM
> Subject: NETTYPE maximum support to user connections ? [27385]
> Sent by: ids-bounces@iiug.org
>
> Lets consider the following value of NETTYPE parameter.
>
> NETTYPE tlitcp,8,50,NET>
> What is the maximum number of tcp connections this parameter can supp=
ort
with
> this value?
>
> What would happen when the maximum allowed limit (derived through the=
se
param
> value) would reach ?
>
> Anees
>
>
>
***********************************************************************=
********
> Forum Note: Use "Reply" to post a response in the discussion forum.=
>=
Thanks for your valuable response.
Actually, we were getting the following exceptions in online.log of our IDS
instance. All applications were unable to connect to db using TCP port.
Also we were unable to connect to db using net service from secondary or even
from using its own server/host.
The NETTYPE and VPCLASS settings are as follows
NETTYPE ipcshm,8,50,CPU
NETTYPE tlitcp,8,50,NET
VPCLASS cpu,num=8,aff=17-21,noage
23:35:01 Logical Log 79075 - Backup Started
2012-06-18 23:35:02 Servername:ids_rss3_13
<<IBM Informix Dynamic Server>>> Logical Log 79075 Complete, timestamp:
0x4bda330d.
23:35:02 Logical Log 79075 Complete, timestamp: 0x4bda330d.
23:35:02 Logical Log 79075 - Backup Completed
23:36:27 Checkpoint Completed: duration was 0 seconds.
23:36:27 Mon Jun 18 - loguniq 79076, logpos 0x264018, timestamp: 0x4bdaa042
Interval: 351250
23:36:27 Maximum server connections 1406
23:36:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 517, Llog used 2744
23:41:23 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
23:41:27 Checkpoint Completed: duration was 0 seconds.
23:41:27 Mon Jun 18 - loguniq 79076, logpos 0x10af018, timestamp: 0x4bdc3153
Interval: 351251
23:41:27 Maximum server connections 1406
23:41:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 1,
Plog used 780, Llog used 3660
23:42:24 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 66 times since it was last printed to the
log.
23:43:25 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 62 times since it was last printed to the
log.
23:44:26 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 72 times since it was last printed to the
log.
23:45:27 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 69 times since it was last printed to the
log.
23:46:27 Checkpoint Completed: duration was 0 seconds.
23:46:27 Mon Jun 18 - loguniq 79076, logpos 0x1798018, timestamp: 0x4bdd4b5c
Interval: 351252
23:46:27 Maximum server connections 1406
23:46:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 125, Llog used 1769
What could be the possible cause of this issue?
Hi,
check if you have set LIMITNUMSESSIONS parameter (available since 11.50) or if
you reached a system limit
(should be logged in a system error file like /var/log/messages or
/var/adm/messages).
Also, finderr 25571 tells you to check the USERTHREADS parameter in onconfig.
Although I have not set this parameter in any instance (and do not know the
default value), i have read
that it limits the total number of user threads (over all NETTYPE entries).
Hope this helps,
Marcus
----- Ursprüngliche Mail -----
Von: "ANEES AHMAD" <aanees@i2cinc.com>
An: ids@iiug.org
Gesendet: Mittwoch, 20. Juni 2012 10:48:59
Betreff: Re: NETTYPE maximum support to user connections ? [27398]
Thanks for your valuable response.
Actually, we were getting the following exceptions in online.log of our IDS
instance. All applications were unable to connect to db using TCP port.
Also we were unable to connect to db using net service from secondary or even
from using its own server/host.
The NETTYPE and VPCLASS settings are as follows
NETTYPE ipcshm,8,50,CPU
NETTYPE tlitcp,8,50,NET
VPCLASS cpu,num=8,aff=17-21,noage
23:35:01 Logical Log 79075 - Backup Started
2012-06-18 23:35:02 Servername:ids_rss3_13
<<IBM Informix Dynamic Server>>> Logical Log 79075 Complete, timestamp:
0x4bda330d.
23:35:02 Logical Log 79075 Complete, timestamp: 0x4bda330d.
23:35:02 Logical Log 79075 - Backup Completed
23:36:27 Checkpoint Completed: duration was 0 seconds.
23:36:27 Mon Jun 18 - loguniq 79076, logpos 0x264018, timestamp: 0x4bdaa042
Interval: 351250
23:36:27 Maximum server connections 1406
23:36:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 517, Llog used 2744
23:41:23 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
23:41:27 Checkpoint Completed: duration was 0 seconds.
23:41:27 Mon Jun 18 - loguniq 79076, logpos 0x10af018, timestamp: 0x4bdc3153
Interval: 351251
23:41:27 Maximum server connections 1406
23:41:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 1,
Plog used 780, Llog used 3660
23:42:24 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 66 times since it was last printed to
the
log.
23:43:25 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 62 times since it was last printed to
the
log.
23:44:26 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 72 times since it was last printed to
the
log.
23:45:27 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 69 times since it was last printed to
the
log.
23:46:27 Checkpoint Completed: duration was 0 seconds.
23:46:27 Mon Jun 18 - loguniq 79076, logpos 0x1798018, timestamp: 0x4bdd4b5c
Interval: 351252
23:46:27 Maximum server connections 1406
23:46:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 125, Llog used 1769
What could be the possible cause of this issue?
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.
Hi again,
USERTHREADS seems to be an ancient parameter (7.x Version). So maybe error
documentation should be updated.
Marcus
----- Ursprüngliche Mail -----
Von: "Marcus Haarmann" <marcus.haarmann@midoco.de>
An: ids@iiug.org
Gesendet: Mittwoch, 20. Juni 2012 11:14:21
Betreff: Re: NETTYPE maximum support to user connections ? [27399]
Hi,
check if you have set LIMITNUMSESSIONS parameter (available since 11.50) or if
you reached a system limit
(should be logged in a system error file like /var/log/messages or
/var/adm/messages).
Also, finderr 25571 tells you to check the USERTHREADS parameter in onconfig.
Although I have not set this parameter in any instance (and do not know the
default value), i have read
that it limits the total number of user threads (over all NETTYPE entries).
Hope this helps,
Marcus
----- Ursprngliche Mail -----
Von: "ANEES AHMAD" <aanees@i2cinc.com>
An: ids@iiug.org
Gesendet: Mittwoch, 20. Juni 2012 10:48:59
Betreff: Re: NETTYPE maximum support to user connections ? [27398]
Thanks for your valuable response.
Actually, we were getting the following exceptions in online.log of our IDS
instance. All applications were unable to connect to db using TCP port.
Also we were unable to connect to db using net service from secondary or even
from using its own server/host.
The NETTYPE and VPCLASS settings are as follows
NETTYPE ipcshm,8,50,CPU
NETTYPE tlitcp,8,50,NET
VPCLASS cpu,num=8,aff=17-21,noage
23:35:01 Logical Log 79075 - Backup Started
2012-06-18 23:35:02 Servername:ids_rss3_13
<<IBM Informix Dynamic Server>>> Logical Log 79075 Complete, timestamp:
0x4bda330d.
23:35:02 Logical Log 79075 Complete, timestamp: 0x4bda330d.
23:35:02 Logical Log 79075 - Backup Completed
23:36:27 Checkpoint Completed: duration was 0 seconds.
23:36:27 Mon Jun 18 - loguniq 79076, logpos 0x264018, timestamp: 0x4bdaa042
Interval: 351250
23:36:27 Maximum server connections 1406
23:36:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 517, Llog used 2744
23:41:23 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
23:41:27 Checkpoint Completed: duration was 0 seconds.
23:41:27 Mon Jun 18 - loguniq 79076, logpos 0x10af018, timestamp: 0x4bdc3153
Interval: 351251
23:41:27 Maximum server connections 1406
23:41:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 1,
Plog used 780, Llog used 3660
23:42:24 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 66 times since it was last printed to
the
log.
23:43:25 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 62 times since it was last printed to
the
log.
23:44:26 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 72 times since it was last printed to
the
log.
23:45:27 listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a
user thread.
The error -25571 has been encountered 69 times since it was last printed to
the
log.
23:46:27 Checkpoint Completed: duration was 0 seconds.
23:46:27 Mon Jun 18 - loguniq 79076, logpos 0x1798018, timestamp: 0x4bdd4b5c
Interval: 351252
23:46:27 Maximum server connections 1406
23:46:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked 0,
Plog used 125, Llog used 1769
What could be the possible cause of this issue?
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.
*******************************************************************************
Forum Note: Use "Reply" to post a response in the discussion forum.
> finderr -25571
-25571 Exceeded the maximum number of user threads.
Check the value of the USERTHREADS parameter in the ONCONFIG
configuration file and the value of the userthreads field of the
NETTYPE parameter.
-25571 Cannot create a user thread.
The database server cannot create or spawn a user thread for a client
that is trying to establish a connection.
Probable causes of the error and corrective actions include:
* The database server cannot allocate system resources for the
user thread at the moment. The client can retry the connection
later. When other clients finish their work, some system resources
should become available again. Check to see if the user is the right
person to execute the utility or the program. For information about
who can use what utilities, refer to the Trusted Facility Manual or
your Administrator's Guide.
* A user who is not allowed to use a particular client application
to connect to the database server tried to use the utility
to connect. Client applications include SQL APIs, DB-Access,
and all the database server utilities.
* A request for a Global Language Support (GLS) structure failed.
Refer to the corrective actions for errors -23100, -23101, -23102,
-23104, -23108, and -23110 for possible solutions.
* A user attempting to connect to the database server does not
belong to the database server user group, as defined in
$INFORMIXDIR/dbssodir/seccfg on a UNIX system or in the registry
on a Windows system. Make sure that the user belongs to a user
group that can access the database server. For more information
about DBSSO users, see the Trusted Facility Manual.
Art
Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on my employer, Advanced DataTools, the IIUG, nor any
other organization with which I am associated either explicitly,
implicitly, or by inference. Neither do those opinions reflect those of
other individuals affiliated with any entity with which I am affiliated nor
those of the entities themselves.
On Wed, Jun 20, 2012 at 4:48 AM, ANEES AHMAD <aanees@i2cinc.com> wrote:
> Thanks for your valuable response.
>
> Actually, we were getting the following exceptions in online.log of our IDS
> instance. All applications were unable to connect to db using TCP port.
> Also we were unable to connect to db using net service from secondary or
> even
> from using its own server/host.
>
> The NETTYPE and VPCLASS settings are as follows
>
> NETTYPE ipcshm,8,50,CPU
> NETTYPE tlitcp,8,50,NET
> VPCLASS cpu,num=8,aff=17-21,noage>
> 23:35:01 Logical Log 79075 - Backup Started
> 2012-06-18 23:35:02 Servername:ids_rss3_13
>
> <<IBM Informix Dynamic Server>>> Logical Log 79075 Complete, timestamp:
> 0x4bda330d.
> 23:35:02 Logical Log 79075 Complete, timestamp: 0x4bda330d.
> 23:35:02 Logical Log 79075 - Backup Completed
> 23:36:27 Checkpoint Completed: duration was 0 seconds.
> 23:36:27 Mon Jun 18 - loguniq 79076, logpos 0x264018, timestamp: 0x4bdaa042
> Interval: 351250
>
> 23:36:27 Maximum server connections 1406
> 23:36:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked
> 0,
> Plog used 517, Llog used 2744
>
> 23:41:23 listener-thread: err = -25571: oserr = 0: errstr = : Cannot
> create a
> user thread.
>
> 23:41:27 Checkpoint Completed: duration was 0 seconds.
> 23:41:27 Mon Jun 18 - loguniq 79076, logpos 0x10af018, timestamp:
> 0x4bdc3153
> Interval: 351251
>
> 23:41:27 Maximum server connections 1406
> 23:41:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked
> 1,
> Plog used 780, Llog used 3660
>
> 23:42:24 listener-thread: err = -25571: oserr = 0: errstr = : Cannot
> create a
> user thread.
> The error -25571 has been encountered 66 times since it was last printed to
> the
> log.
>
> 23:43:25 listener-thread: err = -25571: oserr = 0: errstr = : Cannot
> create a
> user thread.
> The error -25571 has been encountered 62 times since it was last printed to
> the
> log.
>
> 23:44:26 listener-thread: err = -25571: oserr = 0: errstr = : Cannot
> create a
> user thread.
> The error -25571 has been encountered 72 times since it was last printed to
> the
> log.
>
> 23:45:27 listener-thread: err = -25571: oserr = 0: errstr = : Cannot
> create a
> user thread.
> The error -25571 has been encountered 69 times since it was last printed to
> the
> log.
>
> 23:46:27 Checkpoint Completed: duration was 0 seconds.
> 23:46:27 Mon Jun 18 - loguniq 79076, logpos 0x1798018, timestamp:
> 0x4bdd4b5c
> Interval: 351252
>
> 23:46:27 Maximum server connections 1406
> 23:46:27 Checkpoint Statistics - Avg. Txn Block Time 0.001, # Txns blocked
> 0,
> Plog used 125, Llog used 1769
>
> What could be the possible cause of this issue?
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--14dae9340a6f3a7f8e04c2e5a9b7
We don't have any parameter like USERTHREADS or LIMITNUMSESSIONS set in
onconfig of the instance. It means the instance is running with default values
of these two parameters.
Below are the NETTYPE settings
NETTYPE tlitcp,8,50,NET
NETTYPE ipcshm,8,50,CPU
At the time of incident the active sessions were 548 and Maximum server
connections were 1406 and instance was showing exceptions like
"listener-thread: err = -25571: oserr = 0: errstr = : Cannot create a user
thread."