Editor opens excessive mainframe threads to retrieve copybooks since Zowe Cli 3.0

[antonkc]

Environment

Z Open Editor 5.0.0~5.2.0
ZOWE Explorer 3.0>

{
"rseapi_hostname": "xxx.xxx.xxx.xxx",
"zos_version": "02.05.00",
"cea_tso_set": false,
"rse_version": "3.3.5",
"rseapi_port": "8195",
"rseapi_version": "1.1.5",
"base_path": "rseapi",
"json_pretty_output": true
}

STC RSEAPI is using Java 11

Description

When

Prerequisite: When IBM Z Open Editor is updated to the last version and after each Zowe cli configuration update.

The configuration in question:

The issue happens the first time a Cobol file with copybooks is opened.

Result

The request to fetch copybooks fails and retries continually making the mainframe unresponsive.

Observations

• Happens with RSE API, it doesn't with ZOSMF.
• A process with the name of fekflatr.rex is called together with the name of the copybook in these threads. This rex is not called in previous versions to fetch copybooks. (1)
• Only happens since version 5, reverting back to version 4 prevents this incident.
• An initial slow response time from the mainframe may be required so the first copybook request fails a retries.
• Renaming fekflatr.rex prevents this issue, but it also prevents fething the list of members from a PDS.
• May or may not be related to the new virtual file system implemented by ZOWE Explorer version 3

1:

Expected behaviour

Any of the following:

• Not making this many threads
• Waiting for each thread instead of jumping to the next
• Actually fetching the copybooks the first time the configuration is changed

[phaumer]

We have to investigate the cause, but marking it temporarily as a bug.