Namenode fails to start in rolling upgrade from HDP 2.5.0 to 2.5.3

[#1]

ENVIRONMENT: HDP 2.5.0 , Ambari 2.4.1

ERRORS:- Logs from Ambari server:-

resource_management.core.exceptions.ExecutionFailed: Execution of 'ambari-sudo.sh su hdfs -l -s /bin/bash -c 'ulimit -c unlimited ; /usr/hdp/2.5.3.0-37/hadoop/sbin/hadoop-daemon.sh --config /usr/hdp/2.5.3.0-37/hadoop/conf start namenode -rollingUpgrade started'' returned 1. -bash: line 0: ulimit: core file size: cannot modify limit: Operation not permitted 
starting namenode, logging to /var/log/hadoop/hdfs/hadoop-hdfs-namenode-llab90hdpc2m3.out

ROOT CAUSE:- Not yet known,reported as Internal bug. (BUG-70647)

WORKAROUND:- Add the following entries to /etc/security/limits.conf to complete the upgrade.

soft core unlimited
hard core unlimited

OR as root user, run the following command on Ambari server host.

ulimit -c unlimited 

Please note that its not a recommended setting for any of the HDP components and just a workaround to complete the upgrade. Please revert the setting afterwards.In case unsure of the execution/implications of this step ,please raise a support case with HWX to assist further.