Hello, IO 量这么大符合预期吗？而且是读硬盘打满。 有没有尝试过调优？ 1. 业务方面的调优，例如对 state 的使用是否合理 2. 系统层面的调优，例如 incremental checkpoint [1]
1. https://ci.apache.org/projects/flink/flink-docs-release-1.9/dev/stream/state/checkpointing.html#state-backend-incremental Thanks, Biao /'bɪ.aʊ/ On Tue, 10 Sep 2019 at 14:39, Wesley Peng <[email protected]> wrote: > > > on 2019/9/10 13:47, 蒋涛涛 wrote: > > 尝试手段： > > > > 1. 手动迁移IO比较高的任务到其他机器，但是yarn任务提交比较随机，只能偶尔为之 > > > > 2. 目前没有SSD，只能用普通STATA盘，目前加了两块盘提示磁盘IO能力，但是单盘对单任务的磁盘IO瓶颈还在 > > > > 还有哪些策略可以解决或者缓解么？ > > It seems the tricks to improve RocksDB's throughput might be helpfu. > > With writes and reads accessing mostly the recent data, our goal is to > let them stay in memory as much as possible without using up all the > memory on the server. The following parameters are worth tuning: > > Block cache size: When uncompressed blocks are read from SSTables, they > are cached in memory. The amount of data that can be stored before > eviction policies apply is determined by the block cache size. The > bigger the better. > > Write buffer size: How big can Memtable get before it is frozen. > Generally, the bigger the better. The tradeoff is that big write buffer > takes more memory and longer to flush to disk and to recover. > > Write buffer number: How many Memtables to keep before flushing to > SSTable. Generally, the bigger the better. Similarly, the tradeoff is > that too many write buffers take up more memory and longer to flush to > disk. > > Minimum write buffers to merge: If most recently written keys are > frequently changed, it is better to only flush the latest version to > SSTable. This parameter controls how many Memtables it will try to merge > before flushing to SSTable. It should be less than the write buffer > number. A suggested value is 2. If the number is too big, it takes > longer to merge buffers and there is less chance of duplicate keys in > that many buffers. > > The list above is far from being exhaustive, but tuning them correctly > can have a big impact on performance. Please refer to RocksDB’s Tuning > Guide for more details on these parameters. Figuring out the optimal > combination of values for all of them is an art in itself. > > please ref: https://klaviyo.tech/flinkperf-c7bd28acc67 > > regards. >
