eBPF在MySQL性能分析的应⽤用.pdf

eBPF在MySQL性能分析的应⽤ ⽬录 • eBPF 应⽤示例 • 观测⼯具的介绍 • eBPF 脚本/ 限制 BPF是什么 • BPF = Berkeley Packet Filter • The Berkeley Packet Filter (BPF) provides a raw interface to data link layers, permitting raw link-layer packets to be sent and received. • Since version 3.18, the Linux kernel includes an extended BPF virtual machine, termed extended BPF (eBPF). It can be used for non-networking purposes /papers/bpf-usenix93.pdf Query延迟分布 慢Query抓取 VFS 延迟分析 Ext4 延迟分析 块设备延迟分析 MySQL⽂件IO压⼒分析 临时表⽂件⽣命周期观测 短连接分析 流量分析 跟踪函数调⽤ CPU消耗分析 On/Off-CPU⽕焰图分析 # /usr/share/bcc/tools/offcputime -df -p `pgrep -nx mysqld` 30 out.stacks [...copy out.stacks to your local system if desired...] # git clone /brendangregg/FlameGraph # cd FlameGraph # ./flamegraph.pl --color=io --title=Off-CPU Time Flame Graph --countname=us out.stacks out.svg 观测⼯具介绍 eBPF vs Other eBPF内部 eBPF脚本 eBPF ⼯具箱 1. execsnoop 2. opensnoop 3. ext4slower 4. biolatency 5. biosnoop 6. cachestat 7. tcpconnect 8. tcpaccept 9. tcpretrans 10. gethostlatency 11. runlat 12. profile eBPF限制 • OS kernel 4.4+ (推荐 4.9+ ) • MySQL 编译 -DENABLE_DTRACE=1 安装 systemtap-sdt-devel 引⽤ • /Articles/603983/ • /iovisor/bcc • /offcpuanalysis.html • https://jvns.ca/blog/2017/07/05/linux-tracing-systems/#dtrace-probes • /ebpf.html • 是某个慢还是所有都慢