If Disabling Apflow has fixed the issue and the logs in /var/log/messages are as below:
From the messages we see the below
 
Sep 22 11:29:19 <local0.err> Cuppertino nsconfigd: _dispatch(): Pattern index already in use, try using other index
Sep 22 11:29:19 <local0.err> Cuppertino last message repeated 10 times
Sep 22 11:29:19 <kern.crit> Cuppertino kernel: ns_cache64_shm: allocated 528 MB, requested 528 MB, max 4392 MB, mem_limit 528 MB
Sep 22 11:29:21 <local0.err> Cuppertino AutoScaleDaemon[80515]: Monitoring daemon started
Sep 22 11:29:21 <user.crit> Cuppertino syshealthd: sysid 675310, IPMI device rev. 1, firmware rev. 3.11, version 2.0
Sep 22 11:29:21 <local0.err> Cuppertino nsumond[80648]: nsumond daemon started
Sep 22 11:29:23 <local0.alert> Cuppertino restart[80333]: Restart: /netscaler/nsstart.sh exited normally.  Exit code (0)
Sep 22 11:29:23 <local0.alert> Cuppertino restart[80333]:   Nsshutdown lock released !
Sep 22 11:29:23 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:29:23 2017 Restart completed with status (0)
Sep 22 11:29:23 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:29:23 2017 Completed restart cmd (/netscaler/nsrestart.sh)
Sep 22 11:30:26 <daemon.err> Cuppertino monit[1010]: 'iked' process PPID changed to 1
Sep 22 11:50:37 <local0.alert> Cuppertino nsppe: PE 0 (pid 80402) got signal 11; signal mask is 0x0 0x0 0x0 0x0
Sep 22 11:50:37 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:37 2017 NSPPE-00 (80402) unexpectedly died due to receiving signal
Sep 22 11:50:37 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:37 2017 There may be a delay restarting process while collecting core dump on NSPPE-00 (80402)
Sep 22 11:50:37 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:37 2017 proc NSPPE-00 (80402) failure. Therefore initiating nCore NetScaler restart according to policy setting (0x29b4)
Sep 22 11:50:37 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:37 2017 NetScaler restart may be delayed if collecting core dump for NSPPE-00 (80402)
Sep 22 11:50:37 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:37 2017 Pitboss declaring system failure: NSPPE-00 (80402) exited
Sep 22 11:50:43 <local0.alert> Cuppertino restart[81275]:   Nsshutdown lock released !
Sep 22 11:50:43 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:43 2017 nscac64p (80532) died due to receiving signal
Sep 22 11:50:43 <local0.alert> Cuppertino [27]: pitboss Fri Sep 22 11:50:43 2017 There may be a delay restarting process while collecting core dump on nscac64p (80532)
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Problem Cause