NowSMS dramatically loves performance for SMS Users

NowSMS dramatically loves performance for SMS Users SearchSearch
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Dave Baddeley
New member
Username: Davebaddeley

Post Number: 23
Registered: 06-2011
Posted on Monday, June 24, 2019 - 09:08 am:   

Hi Support, we have been encountering issues this week with NowSMS v2017.04.07 where SMS Users connecting by SMPP suddenly start to encounter timeouts, as the performance of the SMPP binds seems to have been majorly affected as they appear all actions are extremely laggy. For instance creating a bind, submitting an SMS and disconnecting would usually complete in under a second, and when the performance drop hits this will often exceed 5 seconds!

This affects all SMPP SMS Users, and only started occurring after we increased the amount of SMS Users SMPP binds from ~20 to ~40.

Restarting NowSMS immediately resolves the issue but after approximately 30 hours it reoccurs.

The server is running 12 virtual CPU cores, 8GB RAM and quick storage and performance has not been an issue previously. There are no apparent signs of resource constraints at the time the performance has dropped off.

This is causing production impact for us, so your help identifying why this happening and how to avoid it would be appreciated.
Dave Baddeley
New member
Username: Davebaddeley

Post Number: 24
Registered: 06-2011
Posted on Monday, June 24, 2019 - 09:10 am:   

Ignore the title auto correct in action should have read "NowSMS dramatically loses performance for SMS Users"
Des - NowSMS Support
Board Administrator
Username: Desosms

Post Number: 6019
Registered: 08-2008
Posted on Tuesday, June 25, 2019 - 08:19 pm:   

Hi Dave,

That is very odd. I've discussed this with several of my colleagues, but no one can think of a similar problem having been reported.

There is an increasing delay applied when responding to invalid bind attempts. So, if clients were first trying invalid credentials, before then trying valid credentials you would see delays like this, but only effecting the clients sending invalid credentials.

Actually, that might explain it. Are you using the same client account(s) from many connections? If so, the default limit of 4 connections from any one clients is the problem. In the NowSMS config program, go to "Web", then "SMPP Options", and set "Max Connections Per Client" to a suitably high number.

--
Des
NowSMS Support
Dave Baddeley
New member
Username: Davebaddeley

Post Number: 25
Registered: 06-2011
Posted on Wednesday, June 26, 2019 - 09:58 am:   

Hi Des

So the maximum amount of connections to any one user is 3, and most are 1, so I don't think the maximum connections per client setting is the issue. Then the issue triggers then when I try to bind in a new user the same lagginess is present, so it is an issue that is affecting all SMPP users rather than one specifically. In general we may have about 36 client SMPP connections and about 30 individual SMS Users. Do you think if one user triggers the connection limit of 4 it could affect all users?

We are using the "Separate outbound message queues for each user" and the "User Queue Size Threshold" is set to 30, I don't know if this might be related, but we have always used this.

Also it hasn't reoccurred for a few days, so the trigger can't be the number of connections on its own, but clearly something is triggering a major slow down in servicing SMPP connections.

Thanks

Dave

P.S Where can I download the latest version of NowSMS and see the change log, as I am sure our version is not the latest.
Dave Baddeley
New member
Username: Davebaddeley

Post Number: 26
Registered: 06-2011
Posted on Tuesday, July 02, 2019 - 05:54 pm:   

Any updates Des?
Des - NowSMS Support
Board Administrator
Username: Desosms

Post Number: 6024
Registered: 08-2008
Posted on Tuesday, July 02, 2019 - 06:20 pm:   

No, sorry that I didn't respond.

My thought was that while this particular setting should not have an effect, it might.

SMPP connections are typically long-lived, as opposed to repeated bind/submit/unbind. There is nothing wrong with either way, it is just more unusual. My thought is that depending on how the unbind sequence is handled by the client, it may take longer to complete the previous unbind...eventually leading to a problem.

I think it is a good idea to raise the connection limit to rule this out.

If the problem reoccurs, before restarting, enable the SMSDEBUG.LOG and let it continue to run for at least 5 minutes. Save copies of the SMSDEBUG.LOG and SMPPDEBUG.LOG files before restarting. And let me know so we can investigate.

Also check if CPU utilization is particularly high.

The latest official version is 2018.11.21. Here are shortcuts for change log and dl of latest version:

https://www.nowsms.com/download/changes.txt

https://www.nowsms.com/download/nowsms-install.exe

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Des
NowSMS Support
Dave Baddeley
New member
Username: Davebaddeley

Post Number: 27
Registered: 06-2011
Posted on Wednesday, July 03, 2019 - 09:11 am:   

Thanks Des, will increase the connection limit, and enable logging if it reoccurs.