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»Forums Index »IQFeed Developer »IQFeed Developer Support »IQFeed freezes
Author Topic: IQFeed freezes (10 messages, Page 1 of 1)

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 4, 2011 06:19 AM          Msg. 1 of 10
Hi,

We have had a report from an end user that IQFeed freezes on a regular basis (at least once a week, sometimes more). When it freezes the end user has to manually kill IQfeed (via the task manager).

This end user repeatedly connects/disconnects to IQfeed during market hours (every 15 minutes) so I am wondering if our connect/disconnect logic could be causing IQfeed to lock up? Is there any logging or other information that I could collect to track down this problem?

Regards,

red.

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 4, 2011 10:15 AM          Msg. 2 of 10
Had some feedback from the user, the freeze has happened for 3 days in a row.

DTN_Steve_S
-DTN Guru-
Posts: 2086
Joined: Nov 21, 2005


Posted: Apr 4, 2011 10:55 AM          Msg. 3 of 10
red, can you give us a bit more information. When you say that the feed freezes, does it just stop sending data? Does it max out the CPU (or at least one core of the CPU)? Does memory usage spike during this occurence as well?

You mentioned the user reconnects every 15mins. Is this by design or is it due to a faulty internet connection or for some other reason? Or is it due to the lockups? When this happens does the app send a disconnect and connect message or does the user right-click the IQFeed icon and choose stop/start feed? Or does the user just shut down the app and restart it?

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 4, 2011 02:06 PM          Msg. 4 of 10
Steve,

Thanks for the quick response. I will try and find what happens with the freeze. All I know is that no other application can connect to IQFeed and no GUI interaction is possible with IQFeed and it must be manually killed.

The 15 minute reconnect/disconnect is by the end users design. Basically our application will connect to IQfeed, then 15 minutes later it will exit and restart (and connect to IQfeed again).

I've just gone through our disconnect logic and this is what we do (in C):

1) Unsubscribe to all symbols on the L1 feed.
2) Close the L1 socket
3) Send "S,DISCONNECT\r\n" on the admin socket
4) Close the admin socket

Looking at the code, there is no delay between 3 and 4, I assume therefore that IQfeed might not get the DISCONNECT message. If this is the case, could this cause later issues for IQfeed? Should we be handling the disconnect sequence differently?

Regards,

red.

DTN_Steve_S
-DTN Guru-
Posts: 2086
Joined: Nov 21, 2005


Posted: Apr 4, 2011 02:38 PM          Msg. 5 of 10
The appropriate disconnect logic will depend on what you (or the end user) is trying to accomplish with the reconnect.

Are you attempting to manually restart the feed once every 15mins? If so, what is the purpose of that?

Or are you simply restarting your app every 15 mins and the feed happens to restart as well (which would be by design if there are no other apps running)?

Realistically, there should never be a need to send the S,DISCONNECT message to IQFeed unless you are doing troubleshooting and want to keep IQFeed running but tell it to disconnect from the servers (work offline mode). You don't need to tell the feed your app is disconnecting, you just need to disconnect the socket connections and the feed should handle it gracefully. It will shutdown by design as soon as all the Level 1 connections (from client apps) have been shut down.

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 4, 2011 03:53 PM          Msg. 6 of 10
Yes, our app is restarting every 15 minutes and IQfeed also restarts (which is fine, just that IQfeed freezes now and again).

Ok, I will change our code to close the L1 connections and not bother with the DISCONNECT messages and see if that makes any difference.

DTN_Steve_S
-DTN Guru-
Posts: 2086
Joined: Nov 21, 2005


Posted: Apr 4, 2011 03:59 PM          Msg. 7 of 10
Sorry for the confusion. I don't necessarily think that the disconnect/reconnect process would be causing the problem. I was simply curious about that procedure since it doesn't seem normal.

The answers to the other questions that you don't yet have answers to are probably going to be more telling of what the actual issue with the freezing is.

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 6, 2011 04:34 AM          Msg. 8 of 10
Ok, some more information...

What ever we have done within our application has made things worse:) The end user is now getting these freezes almost every time in his 15 minute cycle...

On a more positive note, I dont think IQFeed is the problem but our app. For what ever reason, IQFeed is running but not in a connected state. If the end user simply clicks on "Start Feed" then data flows correctly into the app (with no interaction from our app). Is it possible for IQfeed to start up, log in and not be in a connected state?

As a side, I've had a play with trying to send "S,CONNECT\r\n" (every second) when the IQFeed status is "Not Connected" and this will cause IQFeed to crash (after 30 seconds or so). If you need the exact steps to reproduce let me know.

Regards,

red.

skunk
-DTN Evangelist-
Posts: 249
Joined: May 7, 2004


Posted: Apr 6, 2011 12:53 PM          Msg. 9 of 10
I've noticed over the past few days that IQConnect (version 4.7.2.0) sometimes starts in a disconnect state. A restart of IQConnect is required to connect successfully.

redblue
-Interested User-
Posts: 51
Joined: Oct 29, 2009


Posted: Apr 14, 2011 11:55 AM          Msg. 10 of 10
Yes, we've had more cases of this today - for some reason IQConnect starts in a disconnect state. The end user has to manually connect. Is there any way around this problem?
 

 

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