[gpfsug-discuss] gpfs client expels
Salvatore Di Nardo
sdinardo at ebi.ac.uk
Thu Aug 21 10:04:47 BST 2014
Thanks for the feedback, but we managed to find a scenario that excludes
network problems.
we have a file called */input_file/* of nearly 100GB:
if from *client A* we do:
cat input_file >> output_file
it start copying.. and we see waiter goeg a bit up,secs but then they
flushes back to 0, so we xcan say that the copy proceed well...
if now we do the same from another client ( or just another shell on the
same client) *client B* :
cat input_file >> output_file
( in other words we are trying to write to the same destination) all
the waiters gets up until one node get expelled.
Now, while its understandable that the destination file is locked for
one of the "cat", so have to wait ( and since the file is BIG , have to
wait for a while), its not understandable why it stop the renewal lease.
Why its doen't return just a timeout error on the copy instead to expel
the node? We can reproduce this every time, and since our users to
operations like this on files over 100GB each you can imagine the result.
As you can imagine even if its a bit silly to write at the same time to
the same destination, its also quite common if we want to dump to a log
file logs and for some reason one of the writers, write for a lot of
time keeping the file locked.
Our expels are not due to network congestion, but because a write
attempts have to wait another one. What i really dont understand is why
to take a so expreme mesure to expell jest because a process is waiteing
"to too much time".
I have ticket opened to IBM for this and the issue is under
investigation, but no luck so far..
Regards,
Salvatore
On 21/08/14 09:20, Jez Tucker (Chair) wrote:
> Hi there,
>
> I've seen the on several 'stock'? 'core'? GPFS system (we need a
> better term now GSS is out) and seen ping 'working', but alongside
> ejections from the cluster.
> The GPFS internode 'ping' is somewhat more circumspect than unix ping
> - and rightly so.
>
> In my experience this has _always_ been a network issue of one sort of
> another. If the network is experiencing issues, nodes will be ejected.
> Of course it could be unresponsive mmfsd or high loadavg, but I've
> seen that only twice in 10 years over many versions of GPFS.
>
> You need to follow the logs through from each machine in time order to
> determine who could not see who and in what order.
> Your best way forward is to log a SEV2 case with IBM support, directly
> or via your OEM and collect and supply a snap and traces as required
> by support.
>
> Without knowing your full setup, it's hard to help further.
>
> Jez
>
> On 20/08/14 08:57, Salvatore Di Nardo wrote:
>> Still problems. Here some more detailed examples:
>>
>> *EXAMPLE 1:*
>>
>> *EBI5-220**( CLIENT)**
>> *Tue Aug 19 11:03:04.980 2014: *Timed out waiting for a
>> reply from node <GSS02B IP> gss02b*
>> Tue Aug 19 11:03:04.981 2014: Request sent to <GSS02A IP>
>> (gss02a in GSS.ebi.ac.uk) to expel <GSS02B IP> (gss02b in
>> GSS.ebi.ac.uk) from cluster GSS.ebi.ac.uk
>> Tue Aug 19 11:03:04.982 2014: This node will be expelled
>> from cluster GSS.ebi.ac.uk due to expel msg from
>> <EBI5-220 IP> (ebi5-220)
>> Tue Aug 19 11:03:09.319 2014: Cluster Manager connection
>> broke. Probing cluster GSS.ebi.ac.uk
>> Tue Aug 19 11:03:10.321 2014: Unable to contact any
>> quorum nodes during cluster probe.
>> Tue Aug 19 11:03:10.322 2014: Lost membership in cluster
>> GSS.ebi.ac.uk. Unmounting file systems.
>> Tue Aug 19 11:03:10 BST 2014: mmcommon preunmount
>> invoked. File system: gpfs1 Reason: SGPanic
>> Tue Aug 19 11:03:12.066 2014: Connecting to <GSS02A IP>
>> gss02a <c1p687>
>> Tue Aug 19 11:03:12.070 2014: Connected to <GSS02A IP>
>> gss02a <c1p687>
>> Tue Aug 19 11:03:17.071 2014: Connecting to <GSS02B IP>
>> gss02b <c1p686>
>> Tue Aug 19 11:03:17.072 2014: Connecting to <GSS03B IP>
>> gss03b <c1p685>
>> Tue Aug 19 11:03:17.079 2014: Connecting to <GSS03A IP>
>> gss03a <c1p684>
>> Tue Aug 19 11:03:17.080 2014: Connecting to <GSS01B IP>
>> gss01b <c1p683>
>> Tue Aug 19 11:03:17.079 2014: Connecting to <GSS01A IP>
>> gss01a <c1p1>
>> Tue Aug 19 11:04:23.105 2014: Connected to <GSS02B IP>
>> gss02b <c1p686>
>> Tue Aug 19 11:04:23.107 2014: Connected to <GSS03B IP>
>> gss03b <c1p685>
>> Tue Aug 19 11:04:23.112 2014: Connected to <GSS03A IP>
>> gss03a <c1p684>
>> Tue Aug 19 11:04:23.115 2014: Connected to <GSS01B IP>
>> gss01b <c1p683>
>> Tue Aug 19 11:04:23.121 2014: Connected to <GSS01A IP>
>> gss01a <c1p1>
>> Tue Aug 19 11:12:28.992 2014: Node <GSS02A IP> (gss02a in
>> GSS.ebi.ac.uk) is now the Group Leader.
>>
>> *GSS02B ( NSD SERVER)*
>> ...
>> Tue Aug 19 11:03:17.070 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:25.016 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:28.080 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:36.019 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:39.083 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:47.023 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:50.088 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:52.218 2014: Killing connection from
>> <EBI5-043 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:03:58.030 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:01.092 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:03.220 2014: Killing connection from
>> <EBI5-043 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:09.034 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:12.096 2014: Killing connection from
>> *<EBI5-220 IP>* because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:14.224 2014: Killing connection from
>> <EBI5-043 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:20.037 2014: Killing connection from
>> <EBI5-102 IP> because the group is not ready for it to
>> rejoin, err 46
>> Tue Aug 19 11:04:23.103 2014: Accepted and connected to
>> *<EBI5-220 IP>* ebi5-220 <c0n618>
>> ...
>>
>> *GSS02a ( NSD SERVER)*
>> Tue Aug 19 11:03:04.980 2014: Expel <GSS02B IP> (gss02b)
>> request from <EBI5-220 IP> (ebi5-220 in
>> ebi-cluster.ebi.ac.uk). Expelling: <EBI5-220 IP>
>> (ebi5-220 in ebi-cluster.ebi.ac.uk)
>> Tue Aug 19 11:03:12.069 2014: Accepted and connected to
>> <EBI5-220 IP> ebi5-220 <c0n618>
>>
>>
>> ===============================================
>> *EXAMPLE 2*:
>>
>> *EBI5-038*
>> Tue Aug 19 11:32:34.227 2014: *Disk lease period expired
>> in cluster GSS.ebi.ac.uk. Attempting to reacquire lease.*
>> Tue Aug 19 11:33:34.258 2014: *Lease is overdue. Probing
>> cluster GSS.ebi.ac.uk*
>> Tue Aug 19 11:35:24.265 2014: Close connection to <GSS02A
>> IP> gss02a <c1n2> (Connection reset by peer). Attempting
>> reconnect.
>> Tue Aug 19 11:35:24.865 2014: Close connection to
>> <EBI5-014 IP> ebi5-014 <c1n457> (Connection reset by
>> peer). Attempting reconnect.
>> ...
>> LOT MORE RESETS BY PEER
>> ...
>> Tue Aug 19 11:35:25.096 2014: Close connection to
>> <EBI5-167 IP> ebi5-167 <c1n155> (Connection reset by
>> peer). Attempting reconnect.
>> Tue Aug 19 11:35:25.267 2014: Connecting to <GSS02A IP>
>> gss02a <c1n2>
>> Tue Aug 19 11:35:25.268 2014: Close connection to <GSS02A
>> IP> gss02a <c1n2> (Connection failed because destination
>> is still processing previous node failure)
>> Tue Aug 19 11:35:26.267 2014: Retry connection to <GSS02A
>> IP> gss02a <c1n2>
>> Tue Aug 19 11:35:26.268 2014: Close connection to <GSS02A
>> IP> gss02a <c1n2> (Connection failed because destination
>> is still processing previous node failure)
>> Tue Aug 19 11:36:24.276 2014: Unable to contact any
>> quorum nodes during cluster probe.
>> Tue Aug 19 11:36:24.277 2014: *Lost membership in cluster
>> GSS.ebi.ac.uk. Unmounting file systems.*
>>
>> *GSS02a*
>> Tue Aug 19 11:35:24.263 2014: Node <EBI5-038 IP>
>> (ebi5-038 in ebi-cluster.ebi.ac.uk) *is being expelled
>> because of an expired lease.* Pings sent: 60. Replies
>> received: 60.
>>
>>
>>
>>
>> In example 1 seems that an NSD was not repliyng to the client, but
>> the servers seems working fine.. how can i trace better ( to solve)
>> the problem?
>>
>> In example 2 it seems to me that for some reason the manager are not
>> renewing the lease in time. when this happens , its not a single client.
>> Loads of them fail to get the lease renewed. Why this is happening?
>> how can i trace to the source of the problem?
>>
>>
>>
>> Thanks in advance for any tips.
>>
>> Regards,
>> Salvatore
>>
>>
>>
>>
>>
>>
>>
>>
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>> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
>
>
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