dbaccess dbname hangs for seconds
User on Informix 11.70.FC5 under Windows 2008 R2 reported random 10–50 second delays when connecting, including launching dbaccess locally on the server, with nothing unusual in the online log and normal checkpoints/activity. Fernando Nunes suspected slow host name resolution (Informix does reverse DNS per connection via the single MSC VP), suggesting checking with netstat -a, fixing DNS/hosts entries, adding MSC VPs and using NS_CACHE; Paul Watson also suggested monitoring DNS via Nagios, adding the server IP to the hosts files of two newly deployed PCs, and disabling IPv6 if only partly configured. The poster said he would check; no confirmed resolution is recorded.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
Hi, I encounter a bizare problem, the connection to database just hangs at
random for some seconds (10 to 50), I have nagios which monitor a
transactionnal web site and we have noticed today some delay in the pagesn,
when I have connected to the database server (Windowsd 2008 R2) and try to
launch dbaccess, it was hanging for 20 seconds before it gaves me the list of
databases, nothing in the log file, the checkpoints are correct (8 to 14
seconds) and the activity is normal, can long requests or workload generates
this phenomena ?
how can diagnose in order to localize the source of the problem.
for info, 3 months ago, I have the same problem, and I have detected hardly
that there is a request when launched this symptom happened but it was logged
in the online log that tere is a connection problem, now everything is ok, and
also the activity was very normal today.
Odds are that some client is connecting from a host which the server
cannot resolve immediately.
Try to verify that all the clients can be quickly resolved by the server.
running a "netstat -a" on the database server can help diagnose this issue.
If it hangs a bit it means it can't resolve the IP addresses to hostnames
quickly enough.
To mitigate that effect, apart fixing the DNS or file resolver, you can add
more MSC virtual processors and make sure you use the NSCACHE if your
version is 11.70 or later.
Regards.
On Fri, Aug 12, 2016 at 1:16 AM, CHALLENGER212 ABDERRAFI <
abderrafi212@gmail.com> wrote:
> Hi, I encounter a bizare problem, the connection to database just hangs at
> random for some seconds (10 to 50), I have nagios which monitor a
> transactionnal web site and we have noticed today some delay in the pagesn,
> when I have connected to the database server (Windowsd 2008 R2) and try to
> launch dbaccess, it was hanging for 20 seconds before it gaves me the list
> of
> databases, nothing in the log file, the checkpoints are correct (8 to 14
> seconds) and the activity is normal, can long requests or workload
> generates
> this phenomena ?
> how can diagnose in order to localize the source of the problem.
>
> for info, 3 months ago, I have the same problem, and I have detected hardly
> that there is a request when launched this symptom happened but it was
> logged
> in the online log that tere is a connection problem, now everything is ok,
> and
> also the activity was very normal today.
>
>
> ************************************************************
> *******************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--
Fernando Nunes
Portugal
http://informix-technology.blogspot.com
My email works... but I don't check it frequently...
--001a1144844818ad330539d4f0b5
the netstat is working well for the clients who conect to this server, but the problem is that from the server itself I have this phenomena. here my configuration for the NETTYPE: NETTYPE soctcp,10,200,NET Server Windows 2008 r2 (52 GB of RAM) with Informix 11.70 FC5.
If I understood you correctly, "netstat -a" run on the database server show slowness and small hangs. If that's the case, the DNS and/or file resolver in your database server has problems. It has NOTHING to do with Informix configuration. But Informix suffers a lot with that because we try to reverse DNS (translate IP addresses into names on each connection). This is done by calling an OS function, and those calls are made by the MSC virtual processor which usually is just one. So you need to fix the database server host resolver. If it uses DNS make sure all the possible DNS servers are available and working.... The OS resolver will call each DNS server configured with a timeout that can be configured but by default it's probably around 3-5s. If your database server is configured to resolve the IP addresses using files, try to make sure your clients are defined in /etc/hosts (if it's UNIX) or something like C:\\\\WINDOWS\\\\System32\\\\Drivers\\\\etc\\\\hosts Once the DNS infra-structure is fixed your Informix problems will be solved. Meanwhile, adding one or two additional MSC VPs may help mascarade the problem. And using NSCACHE on versions 11.70 and higher can also help. Regards. On Fri, Aug 12, 2016 at 1:32 AM, CHALLENGER212 ABDERRAFI < abderrafi212@gmail.com> wrote: > the netstat is working well for the clients who conect to this server, but > the > problem is that from the server itself I have this phenomena. > > here my configuration for the NETTYPE: NETTYPE soctcp,10,200,NET > Server Windows 2008 r2 (52 GB of RAM) with Informix 11.70 FC5. > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... --94eb2c03d3c68dc4510539d53de7
ok, but Why today, I have the same problem 3 months ago and it was because of
a long request which generate realocating memory segment and so the connection
hangs, when we have resolved this request the problem has gone, we have
simulate the problem whith this request at this time, but now every thing is
ok, there is no long request in the database but why when I logon locally on
the server dbaccess to the database from the server itself hang and try to
connect in 10 to 40s ????
Here is my configuration : Where can I add MSC and cache plz
NETTYPE soctcp,10,200,NET
LISTEN_TIMEOUT 10
MAX_INCOMPLETE_CONNECTIONS 1024
FASTPOLL 1
NS_CACHE host=900,service=900,user=900,group=900
I would suspect DNS - nagios has built-in DNS monitor - activate that and see
what it shows
Cheer
Paul
Paul Watson
Oninit www.oninit.com
+1 913 387 7529
On unit® is a Registered Trademark of Oninit LLC
On Aug 11, 2016, at 19:16, CHALLENGER212 ABDERRAFI <abderrafi212@gmail.com>
wrote:
> Hi, I encounter a bizare problem, the connection to database just hangs at
> random for some seconds (10 to 50), I have nagios which monitor a
> transactionnal web site and we have noticed today some delay in the pagesn,
> when I have connected to the database server (Windowsd 2008 R2) and try to
> launch dbaccess, it was hanging for 20 seconds before it gaves me the list of
> databases, nothing in the log file, the checkpoints are correct (8 to 14
> seconds) and the activity is normal, can long requests or workload generates
> this phenomena ?
> how can diagnose in order to localize the source of the problem.
>
> for info, 3 months ago, I have the same problem, and I have detected hardly
> that there is a request when launched this symptom happened but it was logged
> in the online log that tere is a connection problem, now everything is ok,
and
> also the activity was very normal today.
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
Oh - have you IPV6 enabled ? Seen issues if IPV6 is active but not fully
configured. You can disable IPV6 with respect to informix - something like
IPV6_DISABLE=1 in the startup env
Cheers
Paul
Paul Watson
Oninit www.oninit.com
+1 913 387 7529
On unit® is a Registered Trademark of Oninit LLC
On Aug 11, 2016, at 21:21, Paul Watson <paul@oninit.com> wrote:
> I would suspect DNS - nagios has built-in DNS monitor - activate that and
see what it shows
>
> Cheer
> Paul
>
> Paul Watson
> Oninit www.oninit.com
> +1 913 387 7529
>
> On unit® is a Registered Trademark of Oninit LLC
>
> On Aug 11, 2016, at 19:16, CHALLENGER212 ABDERRAFI <abderrafi212@gmail.com>
wrote:
>
>> Hi, I encounter a bizare problem, the connection to database just hangs at
>> random for some seconds (10 to 50), I have nagios which monitor a
>> transactionnal web site and we have noticed today some delay in the pagesn,
>> when I have connected to the database server (Windowsd 2008 R2) and try to
>> launch dbaccess, it was hanging for 20 seconds before it gaves me the list
of
>> databases, nothing in the log file, the checkpoints are correct (8 to 14
>> seconds) and the activity is normal, can long requests or workload generates
>> this phenomena ?
>> how can diagnose in order to localize the source of the problem.
>>
>> for info, 3 months ago, I have the same problem, and I have detected hardly
>> that there is a request when launched this symptom happened but it was
logged
>> in the online log that tere is a connection problem, now everything is ok,
and
>> also the activity was very normal today.
>>
>>
>>
*******************************************************************************
>> Forum Note: Use "Reply" to post a response in the discussion forum.
Ok I'll check but this problem is at happening at random since yesterday, the only change is that a new very small "Windev" in-house software has been deployed in 2 pc, they only connect to informix to launch 3 small and optimised request.
Easy to prove dns then - add the server IP to the hosts files on the two PCs Cheers Paul Paul Watson Oninit www.oninit.com +1 913 387 7529 On unit® is a Registered Trademark of Oninit LLC On Aug 11, 2016, at 21:32, CHALLENGER212 ABDERRAFI <abderrafi212@gmail.com> wrote: > Ok I'll check but this problem is at happening at random since yesterday, the > only change is that a new very small "Windev" in-house software has been > deployed in 2 pc, they only connect to informix to launch 3 small and > optimised request. > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum.
It's not clear to me: "netstat -a" shows small hangs?
On Fri, Aug 12, 2016 at 1:54 AM, CHALLENGER212 ABDERRAFI <
abderrafi212@gmail.com> wrote:
> ok, but Why today, I have the same problem 3 months ago and it was because
> of
> a long request which generate realocating memory segment and so the
> connection
> hangs, when we have resolved this request the problem has gone, we have
> simulate the problem whith this request at this time, but now every thing
> is
> ok, there is no long request in the database but why when I logon locally
> on
> the server dbaccess to the database from the server itself hang and try to
> connect in 10 to 40s ????
>
> Here is my configuration : Where can I add MSC and cache plz
>
> NETTYPE soctcp,10,200,NET
> LISTEN_TIMEOUT 10
> MAX_INCOMPLETE_CONNECTIONS 1024
> FASTPOLL 1
> NS_CACHE host=900,service=900,user=900,group=900>
>
> ************************************************************
> *******************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--
Fernando Nunes
Portugal
http://informix-technology.blogspot.com
My email works... but I don't check it frequently...
--001a113f37cc0f6ffb0539da9e03