listener-thread: err = -27001: oserr = 0: errstr =
A user on IDS 7.31 under HP-UX 11.11 saw repeated "listener-thread: err = -27001 ... Read error occurred during connection attempt" messages in online.log every minute, alongside badly degraded transaction response times, with no sign of lock, user or network overload. An IBM developer explained the listener logs this when a client opens the TCP port but sends no/garbage connect data — e.g. a misconfigured app using the server's port, a port scanner/security scan, or a DoS — and advised using network tracing to find the source. Others reported seeing it with 4Js clients and passed on an Informix support workaround of setting INFORMIXCONRETRY=2 and INFORMIXCONTIME=10. No confirmation of the actual cause or fix in this case is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Respected all, We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and currently in online status. We are getting the following error in the online.log continously after every minute listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred during connection attempt Due to this error , the response time of the transactions HAS increased SUBSTANTIALLY. finderr -27001 says that "database server or the network was very busy" but could not found any such observation. 1.The no of locks in the DB are normal, 2.The no of users connected are with in the range. 3.No tables are locked 4.Onstat -k shows normal no of locks. 5.The network connections are proper/ the network is not too busy. still we are getting this error Repetitively in online.log and the response time has increased. Kindly reply with the reason for this issue and the SOLUTION for it ASAP. Thanking in Advance Vikas Hivarkar.
Have seen this before but exactly don't remember now what was the cause and its fix but in our environment it was something to do with 4JS client connection to 4JS server. --- VIKAS HIVARKAR <vikashivarkar3@gmail.com> wrote: > Respected all, > > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and > currently in online status. > > We are getting the following error in the online.log continously after every > minute > listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred > during connection attempt > > Due to this error , the response time of the transactions HAS increased > SUBSTANTIALLY. > > finderr -27001 says that "database server or the network was very busy" > but could not found any such observation. > 1.The no of locks in the DB are normal, > 2.The no of users connected are with in the range. > 3.No tables are locked > 4.Onstat -k shows normal no of locks. > 5.The network connections are proper/ the network is not too busy. > > still we are getting this error Repetitively in online.log and the response > time has increased. > > Kindly reply with the reason for this issue and the SOLUTION for it ASAP. > Thanking in Advance > > Vikas Hivarkar. > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Have seen this before but exactly don't remember now what was the cause and its fix but in our environment it was something to do with 4JS client connection to 4JS server. --- VIKAS HIVARKAR <vikashivarkar3@gmail.com> wrote: > Respected all, > > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and > currently in online status. > > We are getting the following error in the online.log continously after every > minute > listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred > during connection attempt > > Due to this error , the response time of the transactions HAS increased > SUBSTANTIALLY. > > finderr -27001 says that "database server or the network was very busy" > but could not found any such observation. > 1.The no of locks in the DB are normal, > 2.The no of users connected are with in the range. > 3.No tables are locked > 4.Onstat -k shows normal no of locks. > 5.The network connections are proper/ the network is not too busy. > > still we are getting this error Repetitively in online.log and the response > time has increased. > > Kindly reply with the reason for this issue and the SOLUTION for it ASAP. > Thanking in Advance > > Vikas Hivarkar. > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
Hi, while this can be a real problem in the network layer, it can also be a kind of "denial of service attack". The message says that the listener thread got a connection request and tried to read the initial data that is expected in this connection request. During this read attempt an error occurs. This could be an error of a system call (i.e. network problem), or it can mean that the expected data is not received. The latter can happen when someone/something communicates to the TCP port that IDS listens to, but then does not send proper connect data. Either it sends nothing or just some garbage. Typical scenarios are a real denial of service attack, some other application misconfigured (i.e. wrongly trying to use IDSs port number), or some software (typically installed by some IT department) that "tests the machine security" by sending garbage to arbitrary active ports to see whether there is an answer without proper authentication, something is vulnerable to give (indirect root) access to unauthoraized users, something crashes upon receiving garbage ... In order to find out where these connect requests come from, you need to dive down into some network traffic analysis tools. I think in new versions the message will be enhanced to help with finding such culprits ... :) Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management IBM Deutschland GmbH Chairman of the Supervisory Board: Hans Ulrich Märki Board of Management: Martin Jetter (Chairman), Rudolf Bauer, Christian Diedrich, Christoph Grandpierre, Matthias Hartmann, Thomas Fell, Michael Diemer Corporate Seat: Stuttgart, Germany; Reg.-Gericht: Amtsgericht Stuttgart, HRB-Nr.: 14 562 WEEE-Reg.-Nr. DE 99369940 ids-bounces@iiug.org wrote on 09.06.2007 09:16:01: > Respected all, > > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and > currently in online status. > > We are getting the following error in the online.log continously after every > minute > listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred > during connection attempt > > Due to this error , the response time of the transactions HAS increased > SUBSTANTIALLY. > > finderr -27001 says that "database server or the network was very busy" > but could not found any such observation. > 1.The no of locks in the DB are normal, > 2.The no of users connected are with in the range. > 3.No tables are locked > 4.Onstat -k shows normal no of locks. > 5.The network connections are proper/ the network is not too busy. > > still we are getting this error Repetitively in online.log and the response > time has increased. > > Kindly reply with the reason for this issue and the SOLUTION for it ASAP. > Thanking in Advance > > Vikas Hivarkar. > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum.
Hi Vikas,
I was getting this exact error a few years ago with IDS 7.31.
Coincidentally I was using 4JS BDS 3.5 compiler/4gl and their
"Widows Client" when I was getting the error. I am not sure
if the 4js product had anything to do with the error, but I
spoke to Informix Tech Support and here is a workaround that
they gave me:
#recommended by Tech Support to try to prevent connect error -27001, 040629
#max number of additional connection attempts after initial one
export INFORMIXCONRETRY=2# minimum time for SQL CONNECT to connect to server before returning error,
# connections will be attempted at 0, 20, 40 seconds
export INFORMIXCONTIME=10
Regards,
Jim Cramer
University of Iowa
> -----Original Message-----
> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
> H.G
> Sent: Saturday, June 09, 2007 7:20 PM
> To: ids@iiug.org
> Subject: Re: listener-thread: err = -27001: oserr = 0: .... [9320]
>
> Have seen this before but exactly don't remember now what was the cause
> and
> its fix but in our
> environment it was something to do with 4JS client connection to 4JS
> server.
>
> --- VIKAS HIVARKAR <vikashivarkar3@gmail.com> wrote:
>
> > Respected all,
> >
> > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and
> > currently in online status.
> >
> > We are getting the following error in the online.log continously
> after every
> > minute
> > listener-thread: err = -27001: oserr = 0: errstr = : Read error
> occurred
> > during connection attempt
> >
> > Due to this error , the response time of the transactions HAS
> increased
> > SUBSTANTIALLY.
> >
> > finderr -27001 says that "database server or the network was very
> busy"
> > but could not found any such observation.
> > 1.The no of locks in the DB are normal,
> > 2.The no of users connected are with in the range.
> > 3.No tables are locked
> > 4.Onstat -k shows normal no of locks.
> > 5.The network connections are proper/ the network is not too busy.
> >
> > still we are getting this error Repetitively in online.log and the
> response
> > time has increased.
> >
> > Kindly reply with the reason for this issue and the SOLUTION for it
> ASAP.
> > Thanking in Advance
> >
> > Vikas Hivarkar.
> >
> >
> >
> ***********************************************************************
> ********
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
>
> ***********************************************************************
> ********
> Forum Note: Use "Reply" to post a response in the discussion forum.
Hi, while this can be a real problem in the network layer, it can also be a kind of "denial of service attack". The message says that the listener thread got a connection request and tried to read the initial data that is expected in this connection request. During this read attempt an error occurs. This could be an error of a system call (i.e. network problem), or it can mean that the expected data is not received. The latter can happen when someone/something communicates to the TCP port that IDS listens to, but then does not send proper connect data. Either it sends nothing or just some garbage. Typical scenarios are a real denial of service attack, some other application misconfigured (i.e. wrongly trying to use IDSs port number), or some software (typically installed by some IT department) that "tests the machine security" by sending garbage to arbitrary active ports to see whether there is an answer without proper authentication, something is vulnerable to give (indirect root) access to unauthoraized users, something crashes upon receiving garbage ... In order to find out where these connect requests come from, you need to dive down into some network traffic analysis tools. I think in new versions the message will be enhanced to help with finding such culprits ... :) Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management IBM Deutschland GmbH Chairman of the Supervisory Board: Hans Ulrich Märki Board of Management: Martin Jetter (Chairman), Rudolf Bauer, Christian Diedrich, Christoph Grandpierre, Matthias Hartmann, Thomas Fell, Michael Diemer Corporate Seat: Stuttgart, Germany; Reg.-Gericht: Amtsgericht Stuttgart, HRB-Nr.: 14 562 WEEE-Reg.-Nr. DE 99369940 ids-bounces@iiug.org wrote on 09.06.2007 09:16:01: > Respected all, > > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and > currently in online status. > > We are getting the following error in the online.log continously after every > minute > listener-thread: err = -27001: oserr = 0: errstr = : Read error occurred > during connection attempt > > Due to this error , the response time of the transactions HAS increased > SUBSTANTIALLY. > > finderr -27001 says that "database server or the network was very busy" > but could not found any such observation. > 1.The no of locks in the DB are normal, > 2.The no of users connected are with in the range. > 3.No tables are locked > 4.Onstat -k shows normal no of locks. > 5.The network connections are proper/ the network is not too busy. > > still we are getting this error Repetitively in online.log and the response > time has increased. > > Kindly reply with the reason for this issue and the SOLUTION for it ASAP. > Thanking in Advance > > Vikas Hivarkar. > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum.
Aaha.. I think, I also exported INFORMIXCONRETRY and possibility (not 100%
sure) modified
???timeout?? ONCONFIG parameter.
--- Jim Cramer <jim-cramer@uiowa.edu> wrote:
> Hi Vikas,
>
> I was getting this exact error a few years ago with IDS 7.31.
> Coincidentally I was using 4JS BDS 3.5 compiler/4gl and their
> "Widows Client" when I was getting the error. I am not sure
> if the 4js product had anything to do with the error, but I
> spoke to Informix Tech Support and here is a workaround that
> they gave me:
>
> #recommended by Tech Support to try to prevent connect error -27001, 040629
> #max number of additional connection attempts after initial one
> export INFORMIXCONRETRY=2> # minimum time for SQL CONNECT to connect to server before returning error,
> # connections will be attempted at 0, 20, 40 seconds
> export INFORMIXCONTIME=10>
> Regards,
>
> Jim Cramer
> University of Iowa
>
> > -----Original Message-----
> > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
> > H.G
> > Sent: Saturday, June 09, 2007 7:20 PM
> > To: ids@iiug.org
> > Subject: Re: listener-thread: err = -27001: oserr = 0: .... [9320]
> >
> > Have seen this before but exactly don't remember now what was the cause
> > and
> > its fix but in our
> > environment it was something to do with 4JS client connection to 4JS
> > server.
> >
> > --- VIKAS HIVARKAR <vikashivarkar3@gmail.com> wrote:
> >
> > > Respected all,
> > >
> > > We have Informix Dynamic Server Version 7.31.UC3 on HP UNIX 11.11.and
> > > currently in online status.
> > >
> > > We are getting the following error in the online.log continously
> > after every
> > > minute
> > > listener-thread: err = -27001: oserr = 0: errstr = : Read error
> > occurred
> > > during connection attempt
> > >
> > > Due to this error , the response time of the transactions HAS
> > increased
> > > SUBSTANTIALLY.
> > >
> > > finderr -27001 says that "database server or the network was very
> > busy"
> > > but could not found any such observation.
> > > 1.The no of locks in the DB are normal,
> > > 2.The no of users connected are with in the range.
> > > 3.No tables are locked
> > > 4.Onstat -k shows normal no of locks.
> > > 5.The network connections are proper/ the network is not too busy.
> > >
> > > still we are getting this error Repetitively in online.log and the
> > response
> > > time has increased.
> > >
> > > Kindly reply with the reason for this issue and the SOLUTION for it
> > ASAP.
> > > Thanking in Advance
> > >
> > > Vikas Hivarkar.
> > >
> > >
> > >
> > ***********************************************************************
> > ********
> > > Forum Note: Use "Reply" to post a response in the discussion forum.
> > >
> > >
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam? Yahoo! Mail has the best spam protection around
> > http://mail.yahoo.com
> >
> >
> > ***********************************************************************
> > ********
> > Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
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