Affects Version/s: 2.6.3
Fix Version/s: 2.7.0
Improving throughput on paging mode is one of our concerns since our cluster uses paging a lot.
We found that pageSyncTimer in PagingStoreImpl shared the same executor with pageCursorProvider from thread pool. In heavy load scenario like hundreds of consumers receiving messages simultaneously, it became difficult for pageSyncTimer to get the executor due to race condition. Therefore page sync was delayed and producers suffered low throughput.
To achieve higher performance we assign a specific executor to pageSyncTimer to avoid racing. And we run a small-scale test on a single modified broker.
Broker: 4C/8G/500G SSD
Producer: 200 threads, non-transactional send
Consumer 200 threads, transactional receive
Message text size: 100-200 bytes randomly
|Only Send TPS||Only Receive TPS||Send&Receive TPS|
The chart above shows that on modified broker send TPS improves from “poor” to “extremely fast”, while receive TPS drops from “extremely fast” to “not-bad” under heavy load. Considering consumer systems usually have a long processing chain after receiving messages, we don’t need too fast receive TPS. Instead, we want to guarantee send TPS to cope with traffic peak and lower producer’s delay time. Moreover, send and receive TPS in total raises from 33k to about 43k. From all above this trade-off seems beneficial and acceptable.