It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that swap TiDB needs sufficient memory space for operation. When memory is insufficient, using swap as a buffer might degrade performance. Therefore, it is recommended to disable the system swap permanently by being writ- ten {db- �→ name �→ }. �→ writable �→ - �→ file �→ - �→ max �→ - �→ buffer �→ - �→ size �→ The maxi- mum buffer size used in Writable- FileWrite 322 Configuration item Description {db- �→

It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that swap TiDB needs sufficient memory space for operation. When memory is insufficient, using swap as a buffer might degrade performance. Therefore, it is recommended to disable the system swap permanently by being writ- ten {db- �→ name �→ }. �→ writable �→ - �→ file �→ - �→ max �→ - �→ buffer �→ - �→ size �→ The maxi- mum buffer size used in Writable- FileWrite 305 Configuration item Description {db- �→

It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that swap TiDB needs sufficient memory space for operation. When memory is insufficient, using swap as a buffer might degrade performance. Therefore, it is recommended to disable the system swap permanently by being writ- ten {db- �→ name �→ }. �→ writable �→ - �→ file �→ - �→ max �→ - �→ buffer �→ - �→ size �→ The maxi- mum buffer size used in Writable- FileWrite 291 Configuration item Description {db- �→

block-cache-size 控制，block-cache-size 越大，能够缓存的热点数据越多，对读取操作越有利，同时 占用的系统内存也会越多。 每个 CF 有各自的 write-buffer ，大小通过 write-buffer-size 控制。 1. # 日志级别，可选值为：trace，debug，info，warn，error，off 2. log-level = "info" 3. 4. [server] RocksDB memtable 的大小。 115. write-buffer-size = "128MB" 116. 117. # 最多允许几个 memtable 存在。写入到 RocksDB 的数据首先会记录到 WAL 日志里面，然后会插入到 118. # memtable 里面，当 memtable 的大小到达了 write-buffer-size 限定的大小的时候，当前的 119. # memtable # memtable 的数量到达 max-write-buffer-number 限定的个数的时候，RocksDB 会将新的写入 性能调优 - 287 - 本文档使用 书栈(BookStack.CN) 构建 123. # stall 住，stall 是 RocksDB 的一种流控机制。在导数据的时候可以将 max-write-buffer-number 124. # 的值设置的更大一点，例如 10。

It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that swap TiDB needs sufficient memory space for operation. When memory is insufficient, using swap as a buffer might degrade performance. Therefore, it is recommended to disable the system swap permanently by being writ- ten {db- �→ name �→ }. �→ writable �→ - �→ file �→ - �→ max �→ - �→ buffer �→ - �→ size �→ The maxi- mum buffer size used in Writable- FileWrite 413 Configuration item Description {db- �→

enablePacketDebug parameter. It is a MySQL Connector/J parameter used for debugging that will keep the buffer of the data packet. This might cause the connection to close unexpectedly. DO NOT turn it on. Way It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that swap TiDB needs sufficient memory space for operation. When memory is insufficient, using swap as a buffer might degrade performance. Therefore, it is recommended to disable the system swap permanently by

enablePacketDebug parameter. It is a MySQL Connector/J parameter used for debugging that will keep the buffer of the data packet. This might cause the connection to close unexpectedly. DO NOT turn it on. Way It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that Write Node: it is recommended to configure at least 200 GB of disk space, which is used as a local buffer when adding TiFlash replicas and migrating Region replicas before uploading data to Amazon S3. In

writable- file- max- buffer- size WritableFileWrite 所使 用的 最大 的 buffer 大小 {db- name}.{cf- name}.block- cache- size block cache size 大小 {db- name}.{cf- name}.write- buffer- size memtable 大小 大小 {db- name}.{cf- name}.max- write- buffer- number 最大 memtable 个数 {db- name}.{cf- name}.max- bytes- for- level- base base level (L1) 最大 字节 数 {db- name}.{cf- name}.target- file- size- 到磁盘的速度 比较慢的情况下。如果磁盘写入速度不能改善，并且只有业务峰值会出现这种情况，可以通过调 大对应 CF 的 max-write-buffer-number 来缓解： * 例如 [rocksdb.defaultcf] max-write-buffer-number = 8 （默认值 5），同时请求注意在高峰 期可能会占用更多的内存，因为可能存在于内存中的 memtable 会更多。 •

enablePacketDebug parameter. It is a MySQL Connector/J parameter used for debugging that will keep the buffer of the data packet. This might cause the connection to close unexpectedly. DO NOT turn it on. Way It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that Write Node: it is recommended to configure at least 200 GB of disk space, which is used as a local buffer when adding TiFlash replicas and migrating Region replicas before uploading data to Amazon S3. In

enablePacketDebug parameter. It is a MySQL Connector/J parameter used for debugging that will keep the buffer of the data packet. This might cause the connection to close unexpectedly. DO NOT turn it on. Way It is recommended to use a high-performance SSD as the first disk of the TiFlash data directory to buffer the real-time replication of TiKV data. The performance of this disk should not be lower than that Write Node: it is recommended to configure at least 200 GB of disk space, which is used as a local buffer when adding TiFlash replicas and migrating Region replicas before uploading data to Amazon S3. In