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An interactive tool to analyze Golang goroutine dump.
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README.md

goroutine-inspect

An interactive tool to analyze Golang goroutine dump.

Build and Run

go get github.com/linuxerwang/goroutine-inspect
$GOPATH/bin/goroutine-inspect

Workspace

Workspace is the place to hold imported goroutine dumps. Instructions are provided to maintain these dumps.

In the interactive shell, two kinds of instructions can be issued: commands and statements.

Commands

At present, the following commands are supported.

command function
cd Change current working directory.
clear Clear the workspace.
exit Exit the interactive shell.
help Show help.
ls Show files in current directory.
pwd Show present working directory.
quit Quit the interactive shell.
whos Show all varaibles in workspace.

Statements

Load Goroutine Dump From Files

Load the dump and assign to a variable:

>> original = load("pprof-goroutines-20170510-170245.dump")
>> whos
original

Show the Summary of a Dump Var

Simply type the variable name:

>> original
# of goroutines: 2217

        running: 1
        IO wait: 533
        syscall: 2
   chan receive: 50
         select: 1504
       runnable: 38
     semacquire: 85
      chan send: 4

Copy a Dump Var

To copy the whole dump, simply assign it to a different var:

>> copy1 = original
>> whos
copy        original

It's equivalent to using a copy() function:

>> copy2 = original.copy()
>> whos
copy        copy1        copy2        original

The copy() function allows passing a conditional so that only those meeting the cariteria will be copied:

>> copy3 = original.copy("id>900 && id<2000")

Modify the Dump Goroutine Items

Function delete() accepts a conditional to delete goroutine items in a dump var. Function keep() do the reversed conditional.

>> copy
# of goroutines: 2217

        running: 1
        IO wait: 533
        syscall: 2
   chan receive: 50
         select: 1504
       runnable: 38
     semacquire: 85
      chan send: 4

>> copy.delete("id>100 && id<1000")
Deleted 118 goroutines, kept 2099.
>> copy.keep("id>200")
Deleted 12 goroutines, kept 2087.
>> copy
# of goroutines: 2087

        running: 1
         select: 1411
        IO wait: 500
     semacquire: 85
       runnable: 37
   chan receive: 49
      chan send: 4

Display Goroutine Dump Items

Function show() displays goroutine dump items with optional offset and limit. The default offset is 0, and default limit is 10.

>> original.show() # offset 0, limit 10

goroutine 1803 [select, 10 minutes]:
google.golang.org/grpc/transport.(*http2Server).keepalive(0xc420e59ce0)
        google.golang.org/grpc/transport/http2_server.go:919 +0x488
created by google.golang.org/grpc/transport.newHTTP2Server
        google.golang.org/grpc/transport/http2_server.go:226 +0x97c

...
...

>> original.show(15) # offset 15, limit 10

goroutine 6455709 [running]:
runtime/pprof.writeGoroutineStacks(0xe9a080, 0xc4216f0088, 0x1d, 0x40)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:603 +0x79
runtime/pprof.writeGoroutine(0xe9a080, 0xc4216f0088, 0x2, 0x1d, 0xc4217cede0)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:592 +0x44
runtime/pprof.(*Profile).WriteTo(0xed3780, 0xe9a080, 0xc4216f0088, 0x2, 0xc4217cef80, 0x1)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:302 +0x3b5
www.test.com/bagel/runtime.dumpToFile(0xed0f0ba5e, 0xae05027, 0xee1780, 0xc425bd2060, 0x5, 0x5)
        www.test.com/bagel/runtime/dump.go:58 +0x3f3
created by www.test.com/bagel/runtime.EnableGoroutineDump.func1
        www.test.com/bagel/runtime/dump.go:30 +0x2d6

...
...

>> original.show(15, 1) # offset 15, limit 1

goroutine 6455709 [running]:
runtime/pprof.writeGoroutineStacks(0xe9a080, 0xc4216f0088, 0x1d, 0x40)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:603 +0x79
runtime/pprof.writeGoroutine(0xe9a080, 0xc4216f0088, 0x2, 0x1d, 0xc4217cede0)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:592 +0x44
runtime/pprof.(*Profile).WriteTo(0xed3780, 0xe9a080, 0xc4216f0088, 0x2, 0xc4217cef80, 0x1)
        go1.8.1.linux-amd64/src/runtime/pprof/pprof.go:302 +0x3b5
www.test.com/bagel/runtime.dumpToFile(0xed0f0ba5e, 0xae05027, 0xee1780, 0xc425bd2060, 0x5, 0x5)
        www.test.com/bagel/runtime/dump.go:58 +0x3f3
created by www.test.com/bagel/runtime.EnableGoroutineDump.func1
        www.test.com/bagel/runtime/dump.go:30 +0x2d6

Search Goroutine Dump Items

Similar to show(), but with a conditional to only show items meeting certain criteria:

>> original.search("id < 2000", 15, 1) # offset 15, limit 1

goroutine 6455896 [select]:
net.(*netFD).connect.func2(0xea1980, 0xc424bca540, 0xc422c1af50, 0xc424bca600, 0xc424bca5a0)
        go1.8.1.linux-amd64/src/net/fd_unix.go:133 +0x1d5
created by net.(*netFD).connect
        go1.8.1.linux-amd64/src/net/fd_unix.go:144 +0x239

One useful ability is to filter goroutines by running time:

>> original.search("duration > 10") # duration larger than 10 minutes

goroutine 72 [select, 25 minutes]: 119 times: [72, 54755, 76757, 299, 201, 286, 283, 296, 204, 302, 207, 305, 338, 356, 359, 362, 365, 372, 375, 368, 378, 328, 331, 387, 381
, 390, 384, 403, 393, 334, 406, 396, 399, 337, 418, 341, 436, 344, 439, 421, 424, 409, 427, 452, 430, 433, 442, 455, 445, 458, 448, 461, 464, 468, 483, 471, 499, 486, 502, 5
05, 489, 76462, 76773, 54530, 54572, 55194, 54824, 54481, 42719, 54691, 54859, 55023, 75593, 76750, 55202, 54885, 79006, 54468, 55212, 54473, 54462, 54931, 54864, 55133, 550
97, 54882, 54901, 55209, 54499, 55114, 54564, 76653, 54416, 54527, 75588, 55034, 54868, 54791, 54813, 54698, 54579, 55111, 54443, 54486, 76467, 54654, 54537, 54456, 55126, 5
5117, 54622, 55199, 54556, 54477, 54871, 79498, 76601, 76735, 76996]
google.golang.org/grpc/transport.(*http2Server).keepalive(0xc4202f0420)
        google.golang.org/grpc/transport/http2_server.go:919 +0x488
created by google.golang.org/grpc/transport.newHTTP2Server
        google.golang.org/grpc/transport/http2_server.go:226 +0x97c

Note that the above is after a dedup operation, so it shows the same stack trace existing 119 times. See the "Dedup goroutines" section.

Diff Two Goroutine Dumps

>> l, c, r = x.diff(y)
>> l
# of goroutines: 574

        IO wait: 147
   chan receive: 1
       runnable: 3
         select: 421
        syscall: 2

>> c
# of goroutines: 651

        IO wait: 157
       runnable: 4
         select: 489
     semacquire: 1

>> r
# of goroutines: 992

        IO wait: 229
   chan receive: 49
      chan send: 4
       runnable: 31
        running: 1
         select: 594
     semacquire: 84

It returns three values: the dump var containing goroutines only appear in x (the left side), the dump var containing goroutines appear in both x and y, the dump var containing goroutines only appear in y (the right side).

Dedup goroutines

Normally goroutine dump files contain thousands of goroutine entries, but there are many duplicated traces. Function dedup() helps to identify these duplicated traces by comparing the trace lines, and only keep one copy of them. It greatly reduces the information explosion and make developers much easier to focus on their problems.

>> a
# of goroutines: 2217

        IO wait: 533
   chan receive: 50
      chan send: 4
       runnable: 38
        running: 1
         select: 1504
     semacquire: 85
        syscall: 2

>> a.dedup()
Dedupped 2217, kept 46
>>
>> a
# of goroutines: 46

        IO wait: 6
   chan receive: 2
      chan send: 2
       runnable: 18
        running: 1
         select: 12
     semacquire: 3
        syscall: 2

To show goroutines with 5+ duplicates:

>> a.search("dups >= 5")
   ...

Save the Modified Goroutine Dump to a File

After a dump var is modified, it can be saved to a file:

>> a.save("pprof-deduped.log")

Properties of a Goroutine Dump Item

Each dump item has 5 properties which can be used in conditionals:

property type meaning
id integer The goroutine ID.
dups integer The number of duplicate traces.
duration integer The waiting duration (in minutes) of a goroutine.
lines integer The number of lines of the goroutine's stack trace.
state string The running state of the goroutine.
trace string The concatenated text of the goroutine stack trace.

Functions in Conditionals

The following functions can be used in defining conditionals:

function args return value meaning
contains string, string bool Returns true if the first arg contains the second arg
lower string string Returns the lowercased string of the input.
upper string string Returns the uppercased string of the input.

Example:

>> original.search("contains(lower(trace), 'handlestream')")
You can’t perform that action at this time.