This:
HashSet<String> es = zks.getZKDatabase()
.getEphemerals(request.sessionId);
Is outside the synchronized block that deletes the ephemerals:
synchronized (zks.outstandingChanges) {
for (ChangeRecord c : zks.outstandingChanges) {
if (c.stat == null) { // Doing a delete
es.remove(c.path); }
else if (c.stat.getEphemeralOwner() == request.sessionId) {
es.add(c.path); }
} for (String path2Delete : es) {
addChangeRecord(new ChangeRecord(txnHeader.getZxid(),
path2Delete, null, 0, null));
} }
On Tue, Sep 27, 2011 at 7:26 PM, Mahadev Konar <[email protected]> wrote:
> Camille,
> I am a little confused on the explanation/text. Probably might want
> to update the jira (if kishore opens one) with a little more detail.
>
> thanks
> mahadev
>
> On Tue, Sep 27, 2011 at 2:20 PM, Fournier, Camille F.
> <[email protected]> wrote:
>> So, the node was created by 0x13220b93e610550 at 12:17:56, then that session
>> closed at 12:17:57, the node did not delete, and a bunch of other sessions
>> later tried to create the node. These sessions got nodeexists failures I
>> presume?
>>
>>
>> Forgive the block of text I'm going to write instead of code:
>>
>> I'm going to bet that the problem lies in PrepRequestProcessor. If we get
>> the ephemerals for the session while an ephemeral is still in
>> outstandingChanges and has not been committed, then another thread commits
>> that ephemeral and removes it from outstanding changes before synchronizing
>> in the outstandingChagnes block, we could never put it in the ephemeral set
>> that we are using to reflect ephemerals to delete. I think we need to move
>> the synchronized block up before we get the ephemerals from the database.
>> But this is a bit of speculation at the moment. Can you create a JIRA
>> tracker for me to look at this?
>>
>> Thanks,
>> C
>>
>>
>>
>> -----Original Message-----
>> From: kishore g [mailto:[email protected]]
>> Sent: Monday, September 26, 2011 1:07 AM
>> To: [email protected]
>> Subject: Re: ephemeral node not removed after the client session is long gone
>>
>> Hi,
>>
>> I got the following information from the logs.
>>
>> The node that still exists is
>> /kafka-tracking/consumers/UserPerformanceEvent-<host>/owners/UserPerformanceEvent/529-7
>>
>> I saw that the ephemeral owner is 86167322861045079 which is session id
>> 0x13220b93e610550.
>>
>> After searching in the transaction log of one of the ZK servers found that
>> session expired
>>
>> 9/22/11 12:17:57 PM PDT session 0x13220b93e610550 cxid 0x74 zxid 0x601bd36f7
>> closeSession null
>>
>> On digging further into the logs I found that there were multiple sessions
>> created in quick succession and every session tried to create the same node.
>> But i verified that the sessions were closed and opened in order
>> 9/22/11 12:17:56 PM PDT session 0x13220b93e610550 cxid 0x0 zxid 0x601bd36b5
>> createSession 6000
>> 9/22/11 12:17:57 PM PDT session 0x13220b93e610550 cxid 0x74 zxid 0x601bd36f7
>> closeSession null
>> 9/22/11 12:17:58 PM PDT session 0x13220b93e610551 cxid 0x0 zxid 0x601bd36f8
>> createSession 6000
>> 9/22/11 12:17:59 PM PDT session 0x13220b93e610551 cxid 0x74 zxid 0x601bd373a
>> closeSession null
>> 9/22/11 12:18:00 PM PDT session 0x13220b93e610552 cxid 0x0 zxid 0x601bd373e
>> createSession 6000
>> 9/22/11 12:18:01 PM PDT session 0x13220b93e610552 cxid 0x6c zxid 0x601bd37a0
>> closeSession null
>> 9/22/11 12:18:02 PM PDT session 0x13220b93e610553 cxid 0x0 zxid 0x601bd37e9
>> createSession 6000
>> 9/22/11 12:18:03 PM PDT session 0x13220b93e610553 cxid 0x74 zxid 0x601bd382b
>> closeSession null
>> 9/22/11 12:18:04 PM PDT session 0x13220b93e610554 cxid 0x0 zxid 0x601bd383c
>> createSession 6000
>> 9/22/11 12:18:05 PM PDT session 0x13220b93e610554 cxid 0x6a zxid 0x601bd388f
>> closeSession null
>> 9/22/11 12:18:06 PM PDT session 0x13220b93e610555 cxid 0x0 zxid 0x601bd3895
>> createSession 6000
>> 9/22/11 12:18:07 PM PDT session 0x13220b93e610555 cxid 0x6a zxid 0x601bd38cd
>> closeSession null
>> 9/22/11 12:18:10 PM PDT session 0x13220b93e610556 cxid 0x0 zxid 0x601bd38d1
>> createSession 6000
>> 9/22/11 12:18:11 PM PDT session 0x13220b93e610557 cxid 0x0 zxid 0x601bd38f2
>> createSession 6000
>> 9/22/11 12:18:11 PM PDT session 0x13220b93e610557 cxid 0x51 zxid 0x601bd396a
>> closeSession null
>>
>> Here is the log output for the sessions that tried creating the same node
>>
>> 9/22/11 12:17:54 PM PDT session 0x13220b93e61054f cxid 0x42 zxid 0x601bd366b
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:17:56 PM PDT session 0x13220b93e610550 cxid 0x42 zxid 0x601bd36ce
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:17:58 PM PDT session 0x13220b93e610551 cxid 0x42 zxid 0x601bd3711
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:18:00 PM PDT session 0x13220b93e610552 cxid 0x42 zxid 0x601bd3777
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:18:02 PM PDT session 0x13220b93e610553 cxid 0x42 zxid 0x601bd3802
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:18:05 PM PDT session 0x13220b93e610554 cxid 0x44 zxid 0x601bd385d
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:18:07 PM PDT session 0x13220b93e610555 cxid 0x44 zxid 0x601bd38b0
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>> 9/22/11 12:18:11 PM PDT session 0x13220b93e610557 cxid 0x52 zxid 0x601bd396b
>> create
>> '/kafka-tracking/consumers/UserPerformanceEvent-<hostname>/owners/UserPerformanceEvent/529-7
>>
>> Let me know if you need additional information.
>>
>> Thanks,
>> Kishore G
>>
>> On Sun, Sep 25, 2011 at 12:56 PM, Camille Fournier <[email protected]>wrote:
>>
>>> Can you give us more details, like the information on the client that
>>> created it, any logs around the time they created it/disconnected,
>>> etc?
>>>
>>> On Sun, Sep 25, 2011 at 2:54 PM, Jun Rao <[email protected]> wrote:
>>> > Hi,
>>> >
>>> > We found our ZK server in a state where an ephemeral node still exists
>>> after
>>> > a client session is long gone. I used the cons command on each ZK host to
>>> > list all connections and couldn't find the ephemeralOwner id. We are
>>> using
>>> > ZK 3.3.3. Has anyone seen this problem?
>>> >
>>> > Thanks,
>>> >
>>> > Jun
>>> >
>>>
>>
>
