是分布式计算领域的旗帜性人物和开源社区领袖，同时是国际知名开源项目 Codis 作者。 Codis 是基于 Redis 的分布式集群解决方案， 为用户提供在线弹性伸缩和高性能的缓存服务，该项目 目前已广泛被各大互 联网公司（百度/小米/滴滴/猎豹 等）采用。 核心技术团队均为一线互联网公司基础架构部资深架构师，有技术改变世界的强烈抱负。 2013年以后 2008年至2013年 2008年以前 • 背景：应用最为广泛的数据库；能 业务）和华为商城（VMall）等大型项目落地 京东 全职工程师（10人团队）深度参与，将会在京 东云平台落地，替 换内部 Oracle，继阿里去IOE之后又一重大标志性事件 百度 已经开始整合 TiDB 的技术调研 滴滴、360、乐视、去哪儿 均有浓厚兴趣，后续合作正在洽谈 渠道 多个Pass服务商 主动希望为其客户提供分布式数据库解决方案（云服务） 客户 多个客户 有明确和迫切的需求痛点，主 动提供场景进行 PoC

获取执⾏ SQL 消耗的 cpu stats 信息 Trace ● Use Go trace to collect runtime information. curl http://localhost:10080/debug/pprof/trace\?seconds\=1 --output trace.out go tool trace trace.out ● In Goroutine analysis Goroutine you want to view. Trace - drawback ● Large performance impact. ● May generate a lot of trace data, and then parsing this data is also consume a lot of time. How Go trace works? Time(ms) Event 50 GoUnpark 1 goroutine 没有被 block 了 60 GoStart 1 开始运⾏ goroutine 80 GoEnd 1 结束 goroutine How Go trace works? Time(ms) Event goroutine_id description 0 GoCreate 1 创建⼀个 goroutine 10 GoStart 1 开始运⾏ goroutine

OpenTracing ○ Zipkin ○ Uber Jaeger ● OpenCensus ● OpenTracing + OpenCensus = OpenTelemetry 基本概念：Trace & Span Trace & Span 例子 Jaeger ● CNCF 毕业项目 ● 实现 OpenTracing 标准 ● UI 友好 ● 多种 Sampling 策略 ● 后端存储分离 ● instrumentedsql luna-duclos/instrumentedsql: A sql driver that will wrap any other driver and log/trace all its calls instrumentedsql 原理 在 Driver 相关的调用加 Wrapper 插入 Span 真实的数据库调用对我们来说还是 黑洞 少废话先看东西 Network Ready Goroutine Wakeup 4.368ms go tool trace go tool trace ● 优点：好用，好看（UI） ● 缺点：性能损耗太大，不能一直开着 Trace in Go runtime ● go tool trace 的原理是？ Trace 会 Go Runtime 的代码中打桩收集 CPU time，在 Goroutine 开始执行时记录

63 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints #6840 • Column-level privileges #9766 • XA syntax hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 9.1.1.1.3 BCC/bpftrace Starting from CentOS 7.6 size by setting the write-buffer-size parameter. 9.2.1.3.1 Parameter specification #### Log level: trace, debug, warn, error, info, off. log-level = "info" [server] #### Set listening address #### addr

#6347 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints #6840 • Column-level privileges #9766 • XA syntax hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 9.1.1.1.3 BCC/bpftrace Starting from CentOS 7.6 size by setting the write-buffer-size parameter. 9.2.1.3.1 Parameter specification #### Log level: trace, debug, warn, error, info, off. log-level = "info" [server] #### Set listening address #### addr

62 • Character sets other than utf8, utf8mb4, ascii, latin1 and binary • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints #6840 • Column-level privileges #9766 • XA syntax hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 9.1.1.1.3 BCC/bpftrace Starting from CentOS 7.6 size by setting the write-buffer-size parameter. 9.2.1.3.1 Parameter specification #### Log level: trace, debug, warn, error, info, off. log-level = "info" [server] #### Set listening address #### addr

where does the latency come from? Investigation curl http://0.0.0.0:10080/debug/pprof/trace?seconds=60 Get the trace information Observation： A query is blocked by GC sweep Investigation ● The garbage

config- uration of Placement Rules #7185 @nolouch • Fix the issue that TiDB Dashboard cannot read PD trace data correctly #7253 @nolouch • Fix the issue that PD might panic due to empty Regions obtained Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • SYS schema • Optimizer trace • XML Functions 75 • X-Protocol #1109 • Column-level privileges #9766 • XA syntax (TiDB uses a two-phase hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 11.2.1.1.3 BCC/bpftrace Starting from CentOS 7.6

Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • SYS schema • Optimizer trace • XML Functions • X-Protocol #1109 • Savepoints #6840 • Column-level privileges #9766 • XA syntax hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 9.1.1.1.3 BCC/bpftrace Starting from CentOS 7.6 size by setting the write-buffer-size parameter. 9.2.1.3.1 Parameter specification #### Log level: trace, debug, warn, error, info, off. log-level = "info" [server] #### Set listening address #### addr

#52465 @tiancaiamao • Fix the format of deprecation warnings #52515 @dveeden • Fix the issue that the TRACE command is missing in copr.buildCopTasks #53085 @time-and-fate • Fix the issue that the memory_quota indexes #6347 • Character sets other than ascii, latin1, binary, utf8, utf8mb4, and gbk. • Optimizer trace • XML Functions • X-Protocol #1109 • Column-level privileges #9766 • XA syntax (TiDB uses a two-phase hardware level (CPU/PMU, performance monitoring unit) features and software features (software counters, trace points). For detailed usage, see perf Examples. 11.2.1.1.3 BCC/bpftrace Starting from CentOS 7.6