R12.2 OHS was not coming up after unclean shutdown or due to server crash.

Issue: 

R12.2 OHS  was not coming up after unclean shutdown or due to server crash.

processes in Instance: EBS_web_TEST_OHS1
---------------------------------+--------------------+---------+---------
ias-component                    | process-type       |     pid | status
---------------------------------+--------------------+---------+---------
EBS_web_TEST                     | OHS                |   6194  | Stop 

OHS was in STOP state and we were not able to either bring down or bring up. It shows PID as 6194 which doens't exist in server.

In logs we were getting below errors.

Log file Location /u01/applmgr/TEST/fs1/FMW_Home/webtier/instances/EBS_web_TEST_OHS1/diagnostics/logs/OHS/EBS_web_TEST/

-- console~OHS~1.log:/u01/applmgr/TEST/fs1/FMW_Home/webtier/ohs/bin/apachectl hardstop: httpd (pid 6194?) not running.

EBS_web_TEST.log:[2017-12-08T14:24:32.4446+05:30] [OHS] [WARNING:32] [OHS-9999] [core.c] [host_id: acsebs.oracle.com] [host_addr: 192.168.1.8] [pid: 6194] [tid: 140126851569472] [user: applmgr] [VirtualHost: main]  pid file

/u01/applmgr/TEST/fs1/FMW_Home/webtier/instances/EBS_web_TEST_OHS1/diagnostics/logs/OHS/EBS_web_TEST/httpd.pid overwritten -- Unclean shutdown of previous Apache run?

Caution:
So it is very clear that OHS was not shutdown properly.Due to this some lock file or httpd.pid files with old pid exists. we have to remove this and  bring up.


Solution:
a. First shutdown opmn process using adopmnctl.sh stop
b. Remove httpd.pid file from /u01/applmgr/TEST/fs1/FMW_Home/webtier/instances/EBS_web_TEST_OHS1/diagnostics/logs/OHS/EBS_web_TEST/
c. cd /u01/applmgr/TEST/fs1/FMW_Home/webtier/instances/EBS_web_TEST_OHS1/config/OPMN/opmn/states
d. grep 6194 * -- You will get  the filename from this command.
e. Remove the file and try to start the OHS. It will come up.