1. 前言
最近接连遇到几个客户的环境在排查集群性能问题，总结了一下，直接教大家如何去获取火焰图、扁鹊图（调用关系图），直击要害，就像是内脏的疾病去医院看病，上来先照一个CT，通过分析CT，大概的毛病也就定位的七七八八了。
2. 火焰图/扁鹊图一键收集
2.1. 步骤一：安装部署obdiag
参考文档： https://www.oceanbase.com/docs/obdiag-cn
安装obdiag并配置被诊断集群信息(~/.obdiag/config.yml)，说明：obdiag 是一款25MB大小的针对OceanBase的黑屏命令行的诊断小工具，功能强大，部署简单。
sudo yum install -y yum-utils
sudo yum-config-manager --add-repo https://mirrors.aliyun.com/oceanbase/OceanBase.repo
sudo yum install -y oceanbase-diagnostic-tool
source /usr/local/oceanbase-diagnostic-tool/init.sh
# 配置被诊断集群信息
obdiag config -hxx.xx.xx.xx -uroot@sys -Pxxxx -p*****2.2. 步骤二：一键收集火焰图/扁鹊图
obdiag gather perf收集过程如图：
解压之后的结果
$tree
.
├── flame.data # 火焰图的数据，后面会用到
├── flame.viz
├── sample.data
├── sample.viz # 扁鹊图的数据，后面会用到
└── top.txt2.3. 步骤三：将火焰图/扁鹊图数据可视化
git clone https://github.com/brendangregg/FlameGraph.git
# 火焰图可视化生成
perf script -i flame.data &> perf.unfold
./FlameGraph/stackcollapse-perf.pl perf.unfold &> perf.folded
./FlameGraph/flamegraph.pl perf.folded > perf.svg
火焰图：
扁鹊图
perfdata2graph.py
#!/usr/bin/python
import sys
import os
import subprocess
import datetime
class Edge:
def __init__(self):
self.count = 0
self.to = None
self.label = None
self.penwidth = 1
self.weight = 1.
self.color = "#000000"
class Node:
def __init__(self):
self.identify = ""
self.name = ""
self.count = 0
self.self_count = 0
self.id = None
self.label = None
self.color = "#F8F8F8"
self.edges = {}
def __str__(self):
return "id: %s, name: %s, count %s, edges %s" % (self.id, self.name, self.count, len(self.edges))
class PerfToGraph:
def __init__(self, fmt = "svg", node_drop_pct = 1., edge_drop_pct = None):
self.fmt = fmt
self.all_nodes = {}
self.samples = 1
self.s100 = 100.
self.node_drop_pct = node_drop_pct
self.edge_drop_pct = edge_drop_pct
self.next_edge_color = 0
if edge_drop_pct is None:
self.edge_drop_pct = node_drop_pct / 5.
self.node_drop_cnt = 0
self.edge_drop_cnt = 0
self.colors = [
(0.02, "#FAFAF0"),
(0.2, "#FAFAD2"),
(1.0, "#F9EBB6"),
(2.0, "#F9DB9B"),
(3.0, "#F8CC7F"),
(5.0, "#F7BC63"),
(7.0, "#FF8B01"),
(9.0, "#FA6F01"),
(12.0, "#F55301"),
(15.0, "#F03801"),
(19.0, "#EB1C01"),
(23.0, "#E60001")
]
self.edge_colors = [
"#FF8B01",
"#EB1C01",
"#DC92EF",
"#9653B8",
"#66B031",
"#D9CA0C",
"#BDBDBD",
"#696969",
"#113866",
"#5CBFAC",
"#1120A8",
"#960144",
"#EA52B2"
]
def convert(self):
self.read_stdin()
self.formalize()
self.output()
def set_pen_width(self, e):
pct = e.count * 100. / self.samples
if pct > 10:
e.penwidth = 3 + min(pct, 100) * 2. / 100
elif pct > 1:
e.penwidth = 1 + pct * 2. / 10
else:
e.penwidth = 1
def set_edge_weight(self, e):
e.weight = e.count * 100. / self.samples
if e.weight > 100:
e.weight = 100
elif e.weight > 10:
e.weight = 10 + e.weight / 10.
def set_edge_color(self, e):
i = self.next_edge_color
self.next_edge_color += 1
e.color = self.edge_colors[i % len(self.edge_colors)];
def set_node_color(self, n):
v = n.self_count / self.s100
for p in self.colors:
if v >= p[0]:
n.color = p[1]
def get_node(self, identify, name):
if self.all_nodes.has_key(identify):
return self.all_nodes[identify]
n = Node()
n.identify = identify
n.name = name
self.all_nodes[identify] = n
return n
def add_edge(self, f, t):
if f.edges.has_key(t.identify):
e = f.edges[t.identify]
e.count += 1
else:
e = Edge()
e.to = t
e.count = 1
f.edges[t.identify] = e
def read_stdin(self):
# $ escape not needed?
cmd = "sed -e 's/<.*>//g' -e 's/ (.*$//' -e 's/+0x.*//g' -e '/^[^\t]/d' -e 's/^\s*//'"
sub = subprocess.Popen(cmd, stdout=subprocess.PIPE, shell = True)
prev = None
self.samples = 1
for l in sub.stdout:
l = l.strip()
if (not l) and (not prev):
# avoding continous empty lines
continue
tmp = l.split(' ')
addr = tmp[0]
name = (" ".join(tmp[1:])).strip()
if '[unknown]' == name:
name = addr
if not l:
addr = 'fake_addr'
name = '::ALL::'
# we use name to identify nodes
n = self.get_node(name, name)
if prev == n:
continue
n.count += 1
if prev:
self.add_edge(n, prev)
prev = n
if not l:
self.samples += 1
prev = None
def formalize(self):
self.s100 = self.samples / 100.
self.node_drop_cnt = self.samples * self.node_drop_pct / 100
self.edge_drop_cnt = self.samples * self.edge_drop_pct / 100
i = 0;
for n in self.all_nodes.values():
n. % (i)
i+=1
n.self_count = n.count - sum([x.count for x in n.edges.values()])
n.label = "%s\\nTotal: %.2f%% | Call: %.2f%%\\nSelf: %.2f%%(%s)" % (n.name.replace("::", "\\n"), n.count/self.s100, (n.count - n.self_count)/self.s100, n.self_count/self.s100, n.self_count)
self.set_node_color(n)
for e in n.edges.values():
e.label = "%.2f%%" % (e.count/self.s100)
self.set_pen_width(e)
self.set_edge_weight(e)
self.set_edge_color(e)
def to_dot(self):
out = []
out.append("""
digraph call_graph_for_perf_data {
style = "perf.css";
node [shape = box, style=filled ];
""")
out.append('note [ label = "%s\\nTotal samples: %d\\nDrop nodes with <= %.2f%%(%d)\\nDrop edges with <= %.2f%%(%d)", fillcolor="#00AFFF" ];' % (datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S'), self.samples, self.node_drop_pct, int(self.node_drop_cnt), self.edge_drop_pct, int(self.edge_drop_cnt)))
for n in self.all_nodes.values():
if n.count <= self.node_drop_cnt:
continue
out.append('%s [ label = "%s", tooltip = "%s", fillcolor="%s"];' % (n.id, n.label, n.name, n.color))
for n in self.all_nodes.values():
if n.count <= self.node_drop_cnt:
continue
for e in n.edges.values():
if e.count <= self.edge_drop_cnt or e.to.count <= self.node_drop_cnt:
continue
tip = 'edgetooltip = "%s ==> %s", labeltooltip = "%s ==> %s"' % (n.name, e.to.name, n.name, e.to.name)
out.append('%s -> %s [ penwidth = %.2f, weight = %f, color = "%s", label = "%s", fontcolor = "%s", %s ];' % (n.id, e.to.id, e.penwidth, e.weight, e.color, e.label, e.color, tip))
out.append("}")
return "\n".join(out)
def output(self):
if "dot" == self.fmt:
print self.to_dot()
elif "svg" == self.fmt:
cmd = "dot -T svg"
sub = subprocess.Popen(cmd, stdin=subprocess.PIPE, shell = True)
dot = self.to_dot()
sub.communicate(input = dot)
elif "top" == self.fmt:
try:
for n in sorted(self.all_nodes.values(), key = lambda n : n.self_count, reverse = True):
print "%s %.2f%%" % (n.name, n.self_count/self.s100)
except:
pass
if __name__ == "__main__":
support_fmt = { "svg" : None, "dot" : None, "top" : None }
if len(sys.argv) < 2 or (not support_fmt.has_key(sys.argv[1])):
print "%s dot/svg/top [node_drop_perent] [edge_drop_percent]" % (sys.argv[0])
sys.exit(1)
fmt = sys.argv[1]
nd_pct = len(sys.argv) > 2 and float(sys.argv[2]) or 1.0
ed_pct = len(sys.argv) > 3 and float(sys.argv[3]) or 0.2
c = PerfToGraph(fmt, nd_pct, ed_pct)
c.convert()
# 生成扁鹊图
cat sample.viz | ./perfdata2graph.py svg sample.svg
3. obdiag 一键收集火焰图和扁鹊图原理
其实obdiag收集信息是依赖于远端ob节点上的perf工具，所以务必要在ob节点上安装perf工具。相当于obdiag帮你去各个节点上执行了如下命令：
# 注意：-p 后面是进程ID，改成你要 perf 的进程
## 生成调用图(扁鹊图)
sudo perf record -e cycles -c 100000000 -p 87741 -g -- sleep 20
sudo perf script -F ip,sym -f > sample.viz
## 生成火焰图
sudo perf record -F 99 -p 87741 -g -- sleep 20
sudo perf script > flame.viz
感兴趣的可以通过obdiag gather perf -v 查看详细的obdiag 日志，通过日志你就能大概知道obdiag的执行过程了。
4. 附录
- obdiag 下载地址： https://www.oceanbase.com/softwarecenter
- obdiag 官方文档： https://www.oceanbase.com/docs/obdiag-cn
- obdiag github地址： https://github.com/oceanbase/obdiag
- obdiag SIG 营地： https://oceanbase.yuque.com/org-wiki-obtech-vh7w9r/imzr6c
