This topic describes monitoring metrics related to the cache hit rates within an OceanBase Database tenant. You can specify a statistical period to query statistics about the cache hit rates in a single zone or on a single OBServer of an OceanBase Database tenant.
block_cache
Definition
The block cache hit rate in the specified statistical period.
Description
| Metric | Metric field name | Unit |
|---|---|---|
| block_cache | block_cache_hit_ratio | Percent |
Calculation expression
100 * 1 / (1 + sum(rate(ob_sysstat{stat_id="50009",@LABELS}[@INTERVAL])) by (@GBLABELS) / sum(rate(ob_sysstat{stat_id="50008",@LABELS}[@INTERVAL])) by (@GBLABELS))
row_cache
Definition
The row cache hit rate in the specified statistical period.
Description
| Metric | Metric field name | Unit |
|---|---|---|
| row_cache | row_cache_hit_ratio | Percent |
Calculation expression
100 * 1 / (1 + sum(rate(ob_sysstat{stat_id="50001",@LABELS}[@INTERVAL])) by (@GBLABELS) / sum(rate(ob_sysstat{stat_id="50000",@LABELS}[@INTERVAL])) by (@GBLABELS))
plan_cache
Definition
The plan cache hit rate in the specified statistical period.
Description
| Metric | Metric field name | Unit |
|---|---|---|
| plan_cache | plan_cache_hit_ratio | Percent |
Calculation expression
100 * sum(rate(ob_plan_cache_hit_total{@LABELS}[@INTERVAL])) by (@GBLABELS) / sum(rate(ob_plan_cache_access_total{@LABELS}[@INTERVAL])) by (@GBLABELS)