Hi Simon,

(My first ever post - queue being shot down in flames)

Whilst this doesn't answer any of your questions (directly)

One thing we do tend to look at when we see (what appears) to be a static 
"Queue Length" value, is the data which is actually inflight from an AFM 
perspective, so that we can ascertain whether the reason is something like, a 
user writing huge files to the cache, which take time to sync with home, and 
thus remain in the queue, providing a static "Queue Length"

[root@server ~]# mmafmctl gpfs getstate | awk ' $6 >=50 '
Fileset Name    Fileset Target                                     Fileset 
State  Gateway Node    Queue State    Queue Length   Queue numExec
afmcancergenetics <IP here>:/leo/res_hpc/afm-leo Dirty           csgpfs01       
         Active                60                        126157822
[root@server ~]#

So for instance, by using the tsfindinode command, to have a look at the size 
of the file which is currently "inflight" from an AFM perspective:

[root@server ~]#  mmfsadm dump afm | more


  Fileset: afm-leo 12 (gpfs)
  mode: independent-writer queue: Normal myFileset  MDS: <c0n334>
  home: <IP> proto: nfs port: 2049   lastCmd: 6
  handler: Mounted Dirty     refCount: 5
  queue: delay 300 QLen 0+9 flushThds 4 maxFlushThds 4 numExec 436 qfs 0 err 0
  i/o: readBuf: 33554432 writeBuf: 2097152 sparseReadThresh: 134217728  
pReadThreads 1
  i/o: pReadGWs 0 (All) pReadChunkSize 134217728 pReadThresh: -2 >> Disabled <<
  i/o: prefetchThresh 0 (Prefetch)
  iw: afmIwTakeoverTime 0
Priority Queue:  (listed by execution order) (state: Active)
    Write [601414711.601379492] inflight  (377743888481 @ 0) chunks 0 bytes 0 0 
thread_id 7630
    Write [601717612.601465868] inflight  (462997479227 @ 0) chunks 0 bytes 0 1 
thread_id 10200
    Write [601717612.601465870] inflight  (391663667550 @ 0) chunks 0 bytes 0 2 
thread_id 10287
    Write [601717612.601465871] inflight  (377743888481 @ 0) chunks 0 bytes 0 3 
thread_id 10333
    Write [601717612.601573418] queued  (387002794104 @ 0) chunks 0 bytes 0 4
    Write [601414711.601650195] queued  (342305480538 @ 0) chunks 0 bytes 0 5
    ResetDirty [538455296.-1] queued etype normal normal  19061213
    ResetDirty [601623334.-1] queued etype normal normal  19061213
    RecoveryMarker [-1.-1] queued etype normal normal  19061213
  Normal Queue:  Empty (state: Active)
Fileset: afmdata 20 (gpfs)



#Use the file inode ID to determine the actual file which is inflight between 
cache and home

[root@server cancergenetics]# tsfindinode  -i 601379492 
/gpfs/afm/cancergenetics > inode.out

[root@server ~]# cat /root/inode.out
601379492               0      0xCCB6  
/gpfs/afm/cancergenetics/Claudia/fastq/PD7446i.fastq

[root@server ~]# ls -l /gpfs/afm/cancergenetics/Claudia/fastq/PD7446i.fastq
-rw-r--r-- 1 bbn16cku MED_pg 377743888481 Mar 25 05:48 
/gpfs/afm/cancergenetics/Claudia/fastq/PD7446i.fastq
[root@server

I am not sure if that helps and you probably already know about it inflight 
checking...


Kind Regards,

Leo

Leo Earl | Head of Research & Specialist Computing
Room ITCS 01.16, University of East Anglia, Norwich Research Park, Norwich NR4 
7TJ
+44 (0) 1603 593856


From: [email protected] 
[mailto:[email protected]] On Behalf Of Venkateswara R 
Puvvada
Sent: 10 October 2017 05:56
To: gpfsug main discussion list <[email protected]>
Subject: Re: [gpfsug-discuss] AFM fun (more!)

Simon,

>Question 1.
>Can we force the gateway node for the other file-sets to our "02" node.
>I.e. So that we can get the queue services for the other filesets.

AFM automatically maps the fileset to gateway node, and today there is no 
option available for users to assign fileset to a particular gateway node. This 
feature will be supported in future releases.

>Question 2.
>How can we make AFM actually work for the "facility" file-set. If we shut
>down GPFS on the node, on the secondary node, we'll see log entires like:
>2017-10-09_13:35:30.330+0100: [I] AFM: Found 1069575 local remove
>operations...
>So I'm assuming the massive queue is all file remove operations?

These are the files which were created in cache, and were deleted before they 
get replicated to home. AFM recovery will delete them locally. Yes, it is 
possible that most of these operations are local remove operations.Try finding 
those operations using dump command.

 mmfsadm saferdump afm all | grep 'Remove\|Rmdir' | grep local | wc -l


>Alarmingly, we are also seeing entires like:
>2017-10-09_13:54:26.591+0100: [E] AFM: WriteSplit file system rds-cache
>fileset rds-projects-2017 file IDs [5389550.5389550.-1.-1,R] name  remote
>error 5

Traces are needed to verify IO errors. Also try disabling the parallel IO and 
see if replication speed improves.

mmchfileset device fileset -p afmParallelWriteThreshold=disable

~Venkat ([email protected]<mailto:[email protected]>)



From:        "Simon Thompson (IT Research Support)" 
<[email protected]<mailto:[email protected]>>
To:        
"[email protected]<mailto:[email protected]>" 
<[email protected]<mailto:[email protected]>>
Date:        10/09/2017 06:27 PM
Subject:        [gpfsug-discuss] AFM fun (more!)
Sent by:        
[email protected]<mailto:[email protected]>
________________________________




Hi All,

We're having fun (ok not fun ...) with AFM.

We have a file-set where the queue length isn't shortening, watching it
over 5 sec periods, the queue length increases by ~600-1000 items, and the
numExec goes up by about 15k.

The queues are steadily rising and we've seen them over 1000000 ...

This is on one particular fileset e.g.:

mmafmctl rds-cache getstate
                      Mon Oct  9 08:43:58 2017

Fileset Name    Fileset Target                                Cache State
       Gateway Node    Queue Length   Queue numExec
------------    --------------
-------------        ------------    ------------   -------------
rds-projects-facility gpfs:///rds/projects/facility           Dirty
       bber-afmgw01    3068953        520504
rds-projects-2015 gpfs:///rds/projects/2015                   Active
       bber-afmgw01    0              3
rds-projects-2016 gpfs:///rds/projects/2016                   Dirty
       bber-afmgw01    1482           70
rds-projects-2017 gpfs:///rds/projects/2017                   Dirty
       bber-afmgw01    713            9104
bear-apps                 gpfs:///rds/bear-apps                         Dirty
 bber-afmgw02    3              2472770871
user-homes                 gpfs:///rds/homes                             Active
  bber-afmgw02    0              19
bear-sysapps    gpfs:///rds/bear-sysapps                      Active
       bber-afmgw02    0              4



This is having the effect that other filesets on the same "Gateway" are
not getting their queues processed.

Question 1.
Can we force the gateway node for the other file-sets to our "02" node.
I.e. So that we can get the queue services for the other filesets.

Question 2.
How can we make AFM actually work for the "facility" file-set. If we shut
down GPFS on the node, on the secondary node, we'll see log entires like:
2017-10-09_13:35:30.330+0100: [I] AFM: Found 1069575 local remove
operations...

So I'm assuming the massive queue is all file remove operations?

Alarmingly, we are also seeing entires like:
2017-10-09_13:54:26.591+0100: [E] AFM: WriteSplit file system rds-cache
fileset rds-projects-2017 file IDs [5389550.5389550.-1.-1,R] name  remote
error 5

Anyone any suggestions?

Thanks

Simon


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