
# Release Notes of v1.12.0

The following are the highlights in this release:

## HTTP Support

We exposed many metadata of a Pegasus cluster and some system states of a Pegasus server through HTTP interfaces. Thanks to @Skysheepwang.

Related PR: [XiaoMi/rdsn#280](https://github.com/XiaoMi/rdsn/pull/280), [#360](https://github.com/XiaoMi/pegasus/pull/360), [XiaoMi/rdsn#321](https://github.com/XiaoMi/rdsn/pull/321), [XiaoMi/rdsn#296](https://github.com/XiaoMi/rdsn/pull/296)

Related Docs: <https://pegasus-kv.github.io/api/http>

## Multi-tenant Support

In XiaoMi as our user base grows, improvements on our multi-tenant support become increasingly needed for stability. For example, we lack monitoring support for table-level latency (only server-level latency). When a table is observed unreasonably slow, we need to refine our slow query mechanism in order to dynamically configure the "slow" threshold per table without system reboot. Another requirement is to support size-based write throttling to reduce the influence of a high-throughput-low-QPS table to other tables in the same cluster.

Related PR: [XiaoMi/rdsn#314](https://github.com/XiaoMi/rdsn/pull/314), [XiaoMi/rdsn#298](https://github.com/XiaoMi/rdsn/pull/298), [#400](https://github.com/XiaoMi/pegasus/pull/400), [XiaoMi/rdsn#336](https://github.com/XiaoMi/rdsn/pull/336), [XiaoMi/rdsn#340](https://github.com/XiaoMi/rdsn/pull/340)

Docs on table-level latency: TBD

Docs on table-level slow query: TBD

Docs on size-based throttling: TBD

## Prometheus Support

Pegasus is continuously lowering our access costs for community users. In this release, we provide our experimental support on Promentheus, thanks to @ChenQShmily.

Related PR: [XiaoMi/rdsn#287](https://github.com/XiaoMi/rdsn/pull/287), [XiaoMi/rdsn#284](https://github.com/XiaoMi/rdsn/pull/284), [#397](https://github.com/XiaoMi/pegasus/pull/397), [#368](https://github.com/XiaoMi/pegasus/pull/368)

Related Docs: TBD

## CPU Profiling Support

Thanks to @linlinhaohao888.

Related PR: [XiaoMi/rdsn#290](https://github.com/XiaoMi/rdsn/pull/290)

Related Docs: TBD

## Bug Fixes

- fix: meta unnecessary assert [XiaoMi/rdsn#332](https://github.com/XiaoMi/rdsn/pull/332)
- fix(coldbackup): delay clean request when chkpting [XiaoMi/rdsn#327](https://github.com/XiaoMi/rdsn/pull/327)

## Upgrade from the previous version

No configuration update is needed in this release.

For table-level latency, some new perf-counters are added. Every read/write operation to a table has  two perf-counters (p99&p999) for latency.

```txt
replica*eon.replica*table.level.RPC_RRDB_RRDB_PUT.latency(ns)@${for.each.table}
replica*eon.replica*table.level.RPC_RRDB_RRDB_PUT.latency(ns)@${for.each.table}.p999
replica*eon.replica*table.level.RPC_RRDB_RRDB_GET.latency(ns)@${for.each.table}
replica*eon.replica*table.level.RPC_RRDB_RRDB_GET.latency(ns)@${for.each.table}.p999
```