2.6 KiB
Regexp in complex query
https://blueprints.launchpad.net/ceilometer/+spec/regexp-in-complex-query
Problem description
Currently some instance or network related service have extra identifier in resource_id. Example is disk.device.* metrics. They have resource_id with format - <instance_id>-<disk-id>. We can't make query for getting all samples from these meters with specified instance_id because disks have different ids. This behavior not easy for end users and adds troubles for someone who wants know more information about cluster work.
Proposed change
To support complex queries described above we should add new regex operator with corresponding "=~" designation.
Implementation depends on backend:
1) MongoDB and DB2. These dbs has $regex query support. It provides regular expression capabilities for pattern matching strings in queries. MongoDB and DB2 use Perl compatible regular expressions (i.e. “PCRE” ) version 8.30 with UTF-8 support. For correct work we map "=~" from filter query to "$regex" in pymongo request.
- SQLAlchemy. This backend supports "regexp" MySQL operator, also it's mapped
- HBase supports regexp queries with RegexStringComparator.
Alternatives
Add extra information to resource metadata
Data model impact
None.
REST API impact
Add new simple operator "=~" in complex queries.
Security impact
None.
Pipeline impact
None
Other end user impact
You may make regex request in complex query.
Performance/Scalability Impacts
Will affect performance for large regular expressions, api service may be affected.
Other deployer impact
None
Developer impact
None
Implementation
Assignee(s)
- Primary assignee:
-
ityaptin
- Ongoing maintainer:
-
enovokshonova
Work Items
- add "=~" to simple operators list in controller
- add regexp operator processing to backends
Future lifecycle
None
Dependencies
None.
Testing
- extend storage scenarios testing to include regexp operator
Documentation Impact
- update complex query notes to include new operator
References
https://blueprints.launchpad.net/ceilometer/+spec/regexp-in-complex-query