Access of EXAStorage through EXAoperation may fail sometimes

Detail name	Value
Changelog Number	7372
Type	Bug
Status	Open
Affected Versions

Problem Description

Accessing the EXAStorage page in EXAoperation or through XMLRPC can lead to internal errors:

In the case of such an error, XMLRPC functions like getDatabaseBackups, return this or similar errors:

<Fault -1: 'IndexError: list index out of range'> 

 Traceback (most recent call last):
  File "/opt/dba/exasol/bin/util/EXABackup.py", line 182, in main
    eb.backup(database, args.level)
  File "/opt/dba/exasol/bin/util/EXABackup.py", line 73, in backup
    backups = self.exasol.getDatabaseBackups(database)
  File "/opt/dba/exasol/lib/EXASOL.py", line 230, in getDatabaseBackups
    info = s.getBackupInfo(entry[0])
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 1112, in __call__
    return self.__send(self.__name, args)
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 1452, in __request
    verbose=self.__verbose
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 1154, in request
    return self.single_request(host, handler, request_body, verbose)
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 1170, in single_request
    return self.parse_response(resp)
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 1342, in parse_response
    return u.close()
  File "/opt/dba/common/python/lib/python3.7/xmlrpc/client.py", line 656, in close
    raise Fault(**self._stack[0])
xmlrpc.client.Fault: <Fault -1: 'IndexError: list index out of range'>

Workaround

The problem is caused by overlap of unintended data changes; retrying the operation should return proper results.