[Gluster-users] pacemaker VIP routing latency to gluster node.

[Dung Le]

Hello,

I have a pretty straight forward configuration as below:

3 storage nodes running version 3.7.11 with replica of 3 and it using native gluster NFS.
corosync version 1.4.7 and pacemaker version 1.1.12
I have DNS round-robin on 3 VIPs living on the 3 storage nodes.

Here is how I configure my corosync:

SN1 with x.x.x.001
SN2 with x.x.x.002
SN3 with x.x.x.003


******************************************************************************************************************
Below is pcs config output:

Cluster Name: dfs_cluster
Corosync Nodes:
 SN1 SN2 SN3 
Pacemaker Nodes:
 SN1 SN2 SN3 

Resources: 
 Clone: Gluster-clone
  Meta Attrs: clone-max=3 clone-node-max=3 globally-unique=false 
  Resource: Gluster (class=ocf provider=glusterfs type=glusterd)
   Operations: start interval=0s timeout=20 (Gluster-start-interval-0s)
               stop interval=0s timeout=20 (Gluster-stop-interval-0s)
               monitor interval=10s (Gluster-monitor-interval-10s)
 Resource: SN1-ClusterIP (class=ocf provider=heartbeat type=IPaddr2)
  Attributes: ip=x.x.x.001 cidr_netmask=32 
  Operations: start interval=0s timeout=20s (SN1-ClusterIP-start-interval-0s)
              stop interval=0s timeout=20s (SN1-ClusterIP-stop-interval-0s)
              monitor interval=10s (SN1-ClusterIP-monitor-interval-10s)
 Resource: SN2-ClusterIP (class=ocf provider=heartbeat type=IPaddr2)
  Attributes: ip=x.x.x.002 cidr_netmask=32 
  Operations: start interval=0s timeout=20s (SN2-ClusterIP-start-interval-0s)
              stop interval=0s timeout=20s (SN2-ClusterIP-stop-interval-0s)
              monitor interval=10s (SN2-ClusterIP-monitor-interval-10s)
 Resource: SN3-ClusterIP (class=ocf provider=heartbeat type=IPaddr2)
  Attributes: ip=x.x.x.003 cidr_netmask=32 
  Operations: start interval=0s timeout=20s (SN3-ClusterIP-start-interval-0s)
              stop interval=0s timeout=20s (SN3-ClusterIP-stop-interval-0s)
              monitor interval=10s (SN3-ClusterIP-monitor-interval-10s)

Stonith Devices: 
Fencing Levels: 

Location Constraints:
  Resource: SN1-ClusterIP
    Enabled on: SN1 (score:3000) (id:location-SN1-ClusterIP-SN1-3000)
    Enabled on: SN2 (score:2000) (id:location-SN1-ClusterIP-SN2-2000)
    Enabled on: SN3 (score:1000) (id:location-SN1-ClusterIP-SN3-1000)
  Resource: SN2-ClusterIP
    Enabled on: SN2 (score:3000) (id:location-SN2-ClusterIP-SN2-3000)
    Enabled on: SN3 (score:2000) (id:location-SN2-ClusterIP-SN3-2000)
    Enabled on: SN1 (score:1000) (id:location-SN2-ClusterIP-SN1-1000)
  Resource: SN3-ClusterIP
    Enabled on: SN3 (score:3000) (id:location-SN3-ClusterIP-SN3-3000)
    Enabled on: SN1 (score:2000) (id:location-SN3-ClusterIP-SN1-2000)
    Enabled on: SN2 (score:1000) (id:location-SN3-ClusterIP-SN2-1000)
Ordering Constraints:
  start Gluster-clone then start SN1-ClusterIP (kind:Mandatory) (id:order-Gluster-clone-SN1-ClusterIP-mandatory)
  start Gluster-clone then start SN2-ClusterIP (kind:Mandatory) (id:order-Gluster-clone-SN2-ClusterIP-mandatory)
  start Gluster-clone then start SN3-ClusterIP (kind:Mandatory) (id:order-Gluster-clone-SN3-ClusterIP-mandatory)
Colocation Constraints:

Resources Defaults:
 is-managed: true
 target-role: Started
 requires: nothing
 multiple-active: stop_nkart
Operations Defaults:
 No defaults set

Cluster Properties:
 cluster-infrastructure: cman
 dc-version: 1.1.11-97629de
 no-quorum-policy: ignore
 stonith-enabled: false

******************************************************************************************************************
pcs status output:

Cluster name: dfs_cluster
Last updated: Thu Sep 22 16:57:35 2016
Last change: Mon Aug 29 18:02:44 2016
Stack: cman
Current DC: SN1 - partition with quorum
Version: 1.1.11-97629de
3 Nodes configured
6 Resources configured


Online: [ SN1 SN2 SN3 ]

Full list of resources:

 Clone Set: Gluster-clone [Gluster]
     Started: [ SN1 SN2 SN3 ]
 SN1-ClusterIP	(ocf::heartbeat:IPaddr2):	Started SN1 
 SN2-ClusterIP	(ocf::heartbeat:IPaddr2):	Started SN2 
 SN3-ClusterIP	(ocf::heartbeat:IPaddr2):	Started SN3 

******************************************************************************************************************


When I mount the gluster volume, I'm using the VIP name. It will choose one of the storage nodes to establish NFS. 

My issue is:

After mounted gluster volume for 1 - 2 hrs, all the clients are reporting not getting df output as df got hung. I did check the dmessage log from client side and getting the following error :

Sep 20 05:46:45 xxxxx kernel: nfs: server nfsserver001 not responding, still trying
Sep 20 05:49:45 xxxxx kernel: nfs: server nfsserver001 not responding, still trying

I did try to mount the gluster volume using the DNS round-robin to different mountpoint but the mount process was not successful. Then I tried to mount the gluster volume using storage node IP itself (not VIP ip), and I was able to mount the gluster volume. Afterward, I flipped all the clients to mount storage node IP directly and they have been up for more than 12hrs without any issue. 

Any idea what might cause this issue?

Thanks a lot,

~ Vic Le
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