REST API and WEB UI Configuration with USS
Article ID: 216786
Updated On:
Products
Issue/Introduction
We have already configured REST API and WEB UI but we found a potential issue with the way the product is set up to use USS (Unix System Services). It has to do with the ZFS that comes with ESP that needs to be mounted as RDWR in USS. We can see there is the potential of losing some data (logs) when implementing a new release of the product. Let me give you some details of our customer system.
STCs names:
ESPTREST this is the STC for the REST API
ESPTIX this is the STC for the WEB UI
The ZFS that comes with CA ESP WLM is mounted at IPL time at mountpoint :
/_PRDS/ESP/CD7YUSS.
This is the entry in BPXPRMxx in SYS1.PARMLIB:
MOUNT
MOUNTPOINT('/_PRDS/ESP/CD7YUSS')
FILESYSTEM('OMVS.ESP.AAW1.V&SYSR1..CD7YUSS.ZFS')
TYPE(ZFS)
MODE(RDWR)
We have already successfully configured both started tasks and these start and work ok. We see that both STCs create and update files (logs) while running and these files live in the same ZFS .
ESPTREST STC updates files in /_PRDS/ESP/CD7YUSS/rest/ directory when running. Files created/updated seem to be some sort of logs for this started task.
ESPTIX STC updates files in /_PRDS/ESP/CD7YUSS/webUI/DB/ directory when it runs. Likewise, these files seem to be some type of log.
The issue we see is that the ZFS that is mounted as Read/Write will contains a combination of code and run time files required for the STCs to run, plus the other files (logs) created by ESPTREST and ESPTIX STCs while running.
All the software our customer runs is maintained in a repository system, and any update done to the product requires to ship the entire product to the customer system, and implemented on the alternate SYSRES via an IPL. The updated product will include a new ZFS so all the files updated by ESPTREST and ESPTIX in the old ZFS will be lost.
Has this issue been reported by any other customer ? Is there a way around this? We tried mounting the ZFS as READ only but ESPTREST and ESPTIX failed to start and we get the following messages in the started tasks log:
FileNotFoundException: ./esp-rest-api.log (EDC5141I Read-only file system.)
FileNotFoundException: ./audit-esp-rest-api.log (EDC5141I Read-only file system)
When we re-mount the ZFS as RDWR, then both ESPTREST and ESPTIX STCs start ok. But as mentioned before, in the ZFS there is combination of code, run time and locally created files (created by the two started tasks). These files created by ESPTREST and ESPTIX will be lost when we implement a new version/release of ESP
Environment
Release : 12.0
Component : REST API
Resolution
The following in our sample RESTOPTS:
#---------------------------------------------------------------------#
# Enter the path to where the ESP REST API runtime logs #
# will be stored #
# #
# Example: #
# ESPREST_LOGS=/u/users/esp/rest/logs #
#---------------------------------------------------------------------#
export ESPREST_LOGS="${ESPREST_HOME}/logs"
And it seems to work well when set to another path.
#---------------------------------------------------------------------#
# Enter the path to where the ESP REST API runtime logs #
# will be stored #
# #
# Example: #
# ESPREST_LOGS=/u/users/esp/rest/logs #
#---------------------------------------------------------------------#
export ESPREST_LOGS="${ESPREST_HOME}/logs"
this works in my case.
Type Perm Permission Changed-EST5EDT Owner ------Size Filename
Dir 777 rwxrwxrwx 2021-06-02 09:47 SMIMA27 8192 .
Dir 777 rwxrwxrwx 2021-02-16 12:30 SMIMA27 8192 ..
File 644 rw-r--r-- 2021-06-02 09:47 CYBSTQA 0 audit-esp-rest-api.log
File 644 rw-r--r-- 2021-06-02 09:47 CYBSTQA 0 audit-espmsapi.log
File 644 rw-r--r-- 2021-06-02 09:47 CYBSTQA 403 esp-rest-api.log
File 644 rw-r--r-- 2021-06-02 09:47 CYBSTQA 144 espmsapi.log
these has been created into the other uss path
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