Bug 1812286
| Summary: | RFE - Monitor the current DB locks ( nsslapd-db-current-locks ). | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 8 | Reporter: | Têko Mihinto <tmihinto> |
| Component: | 389-ds-base | Assignee: | Simon Pichugin <spichugi> |
| Status: | CLOSED ERRATA | QA Contact: | RHDS QE <ds-qe-bugs> |
| Severity: | medium | Docs Contact: | Marc Muehlfeld <mmuehlfe> |
| Priority: | unspecified | ||
| Version: | 8.2 | CC: | aakkiang, bsmejkal, ekasprzy, mharmsen, mreynolds, msauton, ofalk, pasik, sgouvern, spichugi, tbordaz, vashirov |
| Target Milestone: | rc | Keywords: | FutureFeature, Triaged |
| Target Release: | 8.0 | ||
| Hardware: | x86_64 | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | 389-ds-1.4-8050020210531183345.1a75f91c | Doc Type: | Enhancement |
| Doc Text: |
.Directory Server provides monitoring settings that can prevent database corruption caused by lock exhaustion
This update adds the `nsslapd-db-locks-monitoring-enable` parameter to the `cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config` entry. If it is enabled, which is the default, Directory Server aborts all of the searches if the number of active database locks is higher than the percentage threshold configured in `nsslapd-db-locks-monitoring-threshold`. If an issue is encountered, the administrator can increase the number of database locks in the `nsslapd-db-locks` parameter in the `cn=bdb,cn=config,cn=ldbm database,cn=plugins,cn=config` entry. This can prevent data corruption. Additionally, the administrator now can set a time interval in milliseconds that the thread sleeps between the checks.
For further details, see the parameter descriptions in the link:https://access.redhat.com/documentation/en-us/red_hat_directory_server/11/html/configuration_command_and_file_reference/index[Red Hat Directory Server Configuration, Command, and File Reference].
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2021-11-09 18:10:45 UTC | Type: | Bug |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
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Description
Têko Mihinto
2020-03-10 22:40:13 UTC
db lock gets exhausted because of unindexed internal searches (under a transaction). Indexing those searches is the way to prevent exhaustion. To prevent db lock exhaustion and help admin task a possible solutions would be: - If db lock get exhausted during a txn, it leads to db panic and the later recovery can possibly fail. That leads to a full reinit of the instance where the db locks got exhausted. The server should monitor the db lock and trigger server shutdown (similar to disk full) if the db lock is close to be exhausted. Because of the performance impact, the monitoring should be limited to unindexed (allid(candidate)) internal searches (under a txn) and periodically (after each 1000 evaluated candidate). unindexed should be flagged in ldbm_back_search. transaction can be tested with pblock(SLAPI_TXN), monitoring should be done in iterate, internal op is an operation flag OP_FLAG_INTERNAL. - To help indexing the appropriate attributes, unindexed internal search (under txn) should log a warning with the search filter. - a config parameter should toggle monitoring/shutdown. By default it should be enabled. - Monitoring returns value that may be not exact. The threshold to trigger the shutdown should take into account that the value is not perfect. *** Bug 1831812 has been marked as a duplicate of this bug. *** ============================================================================================================ test session starts =============================================================================================================
platform linux -- Python 3.6.8, pytest-6.2.4, py-1.10.0, pluggy-0.13.1 -- /usr/bin/python3.6
cachedir: .pytest_cache
metadata: {'Python': '3.6.8', 'Platform': 'Linux-4.18.0-308.el8.x86_64-x86_64-with-redhat-8.5-Ootpa', 'Packages': {'pytest': '6.2.4', 'py': '1.10.0', 'pluggy': '0.13.1'}, 'Plugins': {'metadata': '1.11.0', 'html': '3.1.1', 'libfaketime': '0.1.2', 'flaky': '3.7.0'}}
389-ds-base: 1.4.3.23-2.module+el8.5.0+11209+cb479c8d
nss: 3.53.1-17.el8_3
nspr: 4.25.0-2.el8_2
openldap: 2.4.46-16.el8
cyrus-sasl: 2.1.27-5.el8
FIPS: disabled
rootdir: /mnt/tests/rhds/tests/upstream/ds/dirsrvtests, configfile: pytest.ini
plugins: metadata-1.11.0, html-3.1.1, libfaketime-0.1.2, flaky-3.7.0
collected 4 items
dirsrvtests/tests/suites/monitor/db_locks_monitor_test.py::test_exhaust_db_locks_basic[70] PASSED [ 25%]
dirsrvtests/tests/suites/monitor/db_locks_monitor_test.py::test_exhaust_db_locks_basic[80] PASSED [ 50%]
dirsrvtests/tests/suites/monitor/db_locks_monitor_test.py::test_exhaust_db_locks_basic[95] PASSED [ 75%]
dirsrvtests/tests/suites/monitor/db_locks_monitor_test.py::test_exhaust_db_locks_big_pause PASSED [100%]
======================================================================================================= 4 passed in 1009.19s (0:16:49) =======================================================================================================
Marking as Verified:Tested.
As per comment 17, marking as VERIFIED Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory (389-ds-base bug fix and enhancement update), and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2021:4203 |