Ping-Sync loop ?

Question

I have a strange problem with a couple of users.
When they are in push mode, the ping command returns immediately with a status of 2 for their Inbox (not sure if other folders have the problem).
When the subsequent sync is issued for that folder, it returns a status of 1 and the same sync key.
THis causes the direct push implementation to go into a loop, getting triggered continuously.

If we reset the synckey to 0 and start all over again, it seems to behave normally.

Any ideas on what could be causing this? Is this server related or something wrong with the implementation?
thanks!

Goutham S

Answer 1

Hi Gouthem:
I have alerted the Protocol Documentation Team about your question. A member of the team will be in touch soon.

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Regards, Obaid Farooqi

Answer 2

Thanks Obaid,
For your reference, the following is how it proceeds, and this repeats forever


4/15/09 9:57 AM:[1238]:ActiveSync Waiting ..
4/15/09 9:57 AM:[1238]:Making request to (NO AUTH) :https://*******.********.***/Microsoft-Server-ActiveSync?User=joel%40********.***&Cmd=Ping&DeviceId=XXXX&DeviceType=Android
4/15/09 9:57 AM:[1238]:Request returned :HTTP/1.1 200 OK
4/15/09 9:57 AM:[1238]:Response :56 bytes
4/15/09 9:57 AM:[1238]:Processing PING response:Ping/Status=2
4/15/09 9:57 AM:[1238]:Processing PING response:Ping/Folders/Folder=c09191c9f0760c4c8c2a2064c5ec3541-286c
4/15/09 9:57 AM:[1238]:Found change. Wait time was 0 secs
4/15/09 9:57 AM:[1238]:Making request to (NO AUTH) :https://*******.********.***/Microsoft-Server-ActiveSync?User=joel%40********.***&Cmd=Sync&DeviceId=XXXX&DeviceType=Android
4/15/09 9:57 AM:[1238]:Request returned :HTTP/1.1 200 OK
4/15/09 9:57 AM:[1238]:Response :110 bytes
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/Class=Email
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/SyncKey={62D121D2-13B8-4708-BD6F-ED1E5EE88A24}218
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/CollectionId=c09191c9f0760c4c8c2a2064c5ec3541-286c
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/Status=1

4/15/09 9:57 AM:[1238]:ActiveSync Waiting ..
4/15/09 9:57 AM:[1238]:Making request to (NO AUTH) :https://*******.********.***/Microsoft-Server-ActiveSync?User=joel%40********.***&Cmd=Ping&DeviceId=XXXX&DeviceType=Android
4/15/09 9:57 AM:[1238]:Request returned :HTTP/1.1 200 OK
4/15/09 9:57 AM:[1238]:Response :56 bytes
4/15/09 9:57 AM:[1238]:Processing PING response:Ping/Status=2
4/15/09 9:57 AM:[1238]:Processing PING response:Ping/Folders/Folder=c09191c9f0760c4c8c2a2064c5ec3541-286c
4/15/09 9:57 AM:[1238]:Found change. Wait time was 0 secs
4/15/09 9:57 AM:[1238]:Making request to (NO AUTH) :https://*******.********.***/Microsoft-Server-ActiveSync?User=joel%40********.***&Cmd=Sync&DeviceId=XXXX&DeviceType=Android
4/15/09 9:57 AM:[1238]:Request returned :HTTP/1.1 200 OK
4/15/09 9:57 AM:[1238]:Response :110 bytes
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/Class=Email
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/SyncKey={62D121D2-13B8-4708-BD6F-ED1E5EE88A24}218
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/CollectionId=c09191c9f0760c4c8c2a2064c5ec3541-286c
4/15/09 9:57 AM:[1238]:Processing response:Sync/Collections/Collection/Status=1

regards
Goutham S

Answer 3

Goutham,

I am the engineer who has taken ownership of your issue. I am investigating this and will update you as things progress.

Dominic Salemno
Senior Support Escalation Engineer

Answer 4

Any ideas yet ?

Answer 5

Goutham,

I am still investigating this issue, I will follow-up with you shortly in regards to this issue.

Dominic Salemno
Senior Support Escalation Engineer

Answer 6

Goutham,

 

This seems like normal behavior. Please review Section 2.2.1.13 of the [MS-ASCMD].pdf document that explains the Ping command (http://msdn.microsoft.com/en-us/library/dd299441.aspx). Essentially, the Ping command is used to monitor changes against specified folders on the server.

What you are experiencing appears to be a heartbeat interval explained in the same section of the documentation:

 

A Ping response status of 2 indicates that changes have occurred in at least one of the folders that were being monitored. The response will indicate which of these folders in which the changes have occurred.

 

A Ping response status of 1 indicates that the heartbeat interval has expired before any changes have occurred, and that the client should reissue the Ping command.

The heartbeat interval will be implementation specific as this is specified by the client.

 

Does this answer your question?

 

Dominic Salemno
Seniort Support Escalation Engineer

Answer 7

Dominic,
thanks for following up :
Not sure if you got my problem completely. as you mentioned, ping status of 2 should mean there are changes to the folder (note i am getting PING status 2 and not 1)
What happens here is a PING status of 2, then i issue a sync for the folder which has been triggered, and the sync returns no changes (in reality there are no changes either).
After the sync, i issue a PING command again, and it returns 2 immediately, and this goes on in a loop. I dont see how heartbeat comes into play, since i am not dealing with status 1 at all in the above log.
Note, this does not happen to all users, just a subset of users.

regards
Goutham S

Answer 8

Goutham,

Could you send me a more verbose log to [e-mail] ?

Dominic Salemno
Senior Support Escalation Engineer

Answer 9

Goutham,

On which version of Exchange are you seeing this issue? Multiple versions? Or just one?

Dominic Salemno
Senior Support Escalation Engineer

Answer 10

If my memory serves me right, both 2003 and 2007 seem to exhibit this.
I have seen this on sent items, calendar, inbox and contacts, so the type of folder doesnt seem to matter.
thanks!
-Goutham

Answer 11

Dominic,
Would it be possible that http://support.microsoft.com/default.aspx?scid=kb;en-us;827615 could be a reason ping returns repeatedly while sync doesnt ?
regards
Goutham S

Answer 12

Goutham,

I will take this into consideration. I will follow-up with you later this afternoon.

Dominic Salemno
Senior Support Escalation Engineer

Answer 13

Goutham,

Do you have anti-virus software installed?

Dominic Salemno
Senior Support Escalation Engineer

Answer 14

Goutham S - Have you received the assistance you needed regarding this issue?

Thanks - Chris

Answer 15

We're assuming the issue on this thread has been addressed. Please submit a new thread if you still need assistance.

Thanks - Chris