5.6 cluster reports wsrep_cert_deps_distance=1.0 in all cases | Parallel Apply not working
Affects | Status | Importance | Assigned to | Milestone | ||
---|---|---|---|---|---|---|
MySQL patches by Codership | Status tracked in 5.6 | |||||
5.5 |
Fix Released
|
High
|
Teemu Ollakka | |||
5.6 |
Fix Released
|
High
|
Teemu Ollakka | |||
Percona XtraDB Cluster moved to https://jira.percona.com/projects/PXC | Status tracked in 5.6 | |||||
5.5 |
Fix Released
|
High
|
Unassigned | |||
5.6 |
Fix Released
|
High
|
Unassigned |
Bug Description
PXC 5.6.16, Galera 3.3, latest GA release.
Standard Linux 3 node running sysbench 8 threads on one node. Other nodes permanently report wsrep_cert_
| wsrep_cert_
| wsrep_apply_oooe | 0.000000 |
| wsrep_apply_oool | 0.000000 |
| wsrep_apply_window | 1.101769 |
| wsrep_commit_oooe | 0.000000 |
| wsrep_commit_oool | 0.000000 |
| wsrep_commit_window | 1.000000 |
Does this mean parallel apply is not working or wsrep_cert_
summary: |
- 5.6 cluster node that is a slave with parallel worker threads seems to - generate writesets that are not parallelizable + 5.6 cluster reports wsrep_cert_deps_distance=1.0 in all cases |
description: | updated |
summary: |
- 5.6 cluster reports wsrep_cert_deps_distance=1.0 in all cases + 5.6 cluster reports wsrep_cert_deps_distance=1.0 in all cases | Parallel + Apply not working |
I can confirm that on PXC 5.5 wsrep_cert_ deps_distance reports properly with the same sysbench workload:
ip-10-235-58-55 mysql> show global status like 'wsrep_cert%'; ------- ------- ------+ ------- -----+ ------- ------- ------+ ------- -----+ deps_distance | 440.819692 | index_size | 842 | ------- ------- ------+ ------- -----+
+------
| Variable_name | Value |
+------
| wsrep_cert_
| wsrep_cert_
+------
2 rows in set (0.00 sec)
However, on PXC 5.6, whether Galera 2 or Galera 3, I only get a value of '1' for wsrep_cert_ deps_distance.
| wsrep_cert_ deps_distance | 1.000000 |