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From:   Indivar Nair <indivar.nair@techterra.in>
Date:   Thu, 11 Jul 2019 12:19:21 +0530
Message-ID: <CALuPYL1_rvyn9A6gZnMCE8p87WoYjsU4BuUKT2OuxXUDiumO2w@mail.gmail.com>
Subject: rpc.statd dies because of pacemaker monitoring
To:     linux-nfs@vger.kernel.org
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Sender: linux-nfs-owner@vger.kernel.org
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Hi ...,

I have a 2 node Pacemaker cluster built using CentOS 7.6.1810
It serves files using NFS and Samba.

Every 15 - 20 minutes, the rpc.statd service fails, and the whole NFS
service is restarted.
After investigation, it was found that the service fails after a few
rounds of monitoring by Pacemaker.
The Pacemaker's script runs the following command to check whether all
the services are running -
---------------------------------------------------------------------------------------------------------------------------------------
    rpcinfo > /dev/null 2>&1
    rpcinfo -t localhost 100005 > /dev/null 2>&1
    nfs_exec status nfs-idmapd > $fn 2>&1
    rpcinfo -t localhost 100024 > /dev/null 2>&1
---------------------------------------------------------------------------------------------------------------------------------------
The script is scheduled to check every 20 seconds.

This is the message we get in the logs -
-------------------------------------------------------------------------------------------------------------------------------------
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: check_default: access by
127.0.0.1 ALLOWED
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: Received NULL request
from 127.0.0.1
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: check_default: access by
127.0.0.1 ALLOWED (cached)
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: Received NULL request
from 127.0.0.1
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: check_default: access by
127.0.0.1 ALLOWED (cached)
Jul 09 07:33:56 virat-nd01 rpc.mountd[51641]: Received NULL request
from 127.0.0.1
-------------------------------------------------------------------------------------------------------------------------------------

After 10 seconds, we get his message -
-------------------------------------------------------------------------------------------------------------------------------------
Jul 09 07:34:09 virat-nd01 nfsserver(virat-nfs-daemon)[54087]: ERROR:
rpc-statd is not running
-------------------------------------------------------------------------------------------------------------------------------------
Once we get this error, the NFS service is automatically restarted.

"ERROR: rpc-statd is not running" message is from the pacemaker's
monitoring script.
I have pasted that part of the script below.

I disabled monitoring and everything is working fine, since then.

I cant keep the cluster monitoring disabled forever.

Kindly help.

Regards,


Indivar Nair

Part of the pacemaker script that does the monitoring
(/usr/lib/ocf/resources.d/heartbeat/nfsserver)
=======================================================================
nfsserver_systemd_monitor()
{
    local threads_num
    local rc
    local fn

    ocf_log debug "Status: rpcbind"
    rpcinfo > /dev/null 2>&1
    rc=$?
    if [ "$rc" -ne "0" ]; then
        ocf_exit_reason "rpcbind is not running"
        return $OCF_NOT_RUNNING
    fi

    ocf_log debug "Status: nfs-mountd"
    rpcinfo -t localhost 100005 > /dev/null 2>&1
    rc=$?
    if [ "$rc" -ne "0" ]; then
        ocf_exit_reason "nfs-mountd is not running"
        return $OCF_NOT_RUNNING
    fi

    ocf_log debug "Status: nfs-idmapd"
    fn=`mktemp`
    nfs_exec status nfs-idmapd > $fn 2>&1
    rc=$?
    ocf_log debug "$(cat $fn)"
    rm -f $fn
    if [ "$rc" -ne "0" ]; then
        ocf_exit_reason "nfs-idmapd is not running"
        return $OCF_NOT_RUNNING
    fi

    ocf_log debug "Status: rpc-statd"
    rpcinfo -t localhost 100024 > /dev/null 2>&1
    rc=$?
    if [ "$rc" -ne "0" ]; then
        ocf_exit_reason "rpc-statd is not running"
        return $OCF_NOT_RUNNING
    fi

    nfs_exec is-active nfs-server
    rc=$?

    # Now systemctl is-active can't detect the failure of kernel
process like nfsd.
    # So, if the return value of systemctl is-active is 0, check the
threads number
    # to make sure the process is running really.
    # /proc/fs/nfsd/threads has the numbers of the nfsd threads.
    if [ $rc -eq 0 ]; then
        threads_num=`cat /proc/fs/nfsd/threads 2>/dev/null`
        if [ $? -eq 0 ]; then
            if [ $threads_num -gt 0 ]; then
                return $OCF_SUCCESS
            else
                return 3
            fi
        else
            return $OCF_ERR_GENERIC
        fi
    fi

    return $rc
}
=======================================================================