This is an automated email from the ASF dual-hosted git repository.
covener pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/httpd-site.git
The following commit(s) were added to refs/heads/main by this push:
new aedadbe live: procdump and thread apply all bt
aedadbe is described below
commit aedadbefc64987cc599e550ccdad915614aa57d0
Author: Eric Covener <ecovener@us.ibm.com>
AuthorDate: Mon Nov 22 07:55:53 2021 -0500
live: procdump and thread apply all bt
---
content/dev/debugging.md | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/content/dev/debugging.md b/content/dev/debugging.md
index 0372d7b..da7d1a7 100644
--- a/content/dev/debugging.md
+++ b/content/dev/debugging.md
@@ -191,7 +191,13 @@ to display a a live backtrace. For example, on Solaris it looks like
```
Another technique is to use gdb to attach to the running process and then
-using "where" to print the backtrace, as in
+using "thread apply all bt" to print the backtrace, as in:
+
+```
+sudo gdb /path/to/bin/httpd 10623 --batch --eval-command "where" --eval-command "thread apply all bt" --eval-command "detach" --eval-command "quit" | tee gdb-output.txt
+```
+
+Or interactively:
```
% gdb httpd 10623
@@ -205,14 +211,7 @@ using "where" to print the backtrace, as in
/usr/local/apache/src/10623: No such file or directory.
Attaching to program `/usr/local/apache/src/httpd', process 10623
Reading symbols from /usr/lib/libsocket.so.1...done.
- Reading symbols from /usr/lib/libnsl.so.1...done.
- Reading symbols from /usr/lib/libc.so.1...done.
- Reading symbols from /usr/lib/libdl.so.1...done.
- Reading symbols from /usr/lib/libintl.so.1...done.
- Reading symbols from /usr/lib/libmp.so.1...done.
- Reading symbols from /usr/lib/libw.so.1...done.
- Reading symbols from
- /usr/platform/SUNW,Ultra-1/lib/libc_psr.so.1...done.
+ ...
0xef5b68d8 in ()
(gdb) where
#0 0xef5b68d8 in ()
@@ -220,7 +219,9 @@ using "where" to print the backtrace, as in
#2 0x4257c in wait_or_timeout (status=0x0) at http_main.c:2357
#3 0x44318 in standalone_main (argc=392552, argv=0x75800) at...
#4 0x449fc in main (argc=3, argv=0xefffeee4) at http_main.c:4534
- (gdb)
+ (gdb) thread apply all bt
+ (gdb) detach
+ (gdb> quit
```
# Getting a live backtrace on Windows {#backtrace-win}
@@ -231,6 +232,8 @@ usually found.) These.pdb files should unpack alongside the.exe,.dll,.so
binary files they represent, e.g., mod_usertrack.pdb will unpack alongside
mod_usertrack.so.
+1. Optional: Obtain `procdump` from Sysinternals.
+
1. Invoke `drwtsn32` and ensure you are creating a crash dump file, you are
dumping all thread contexts, your log and crash dump paths make sense, and
(depending on the nature of the bug) you pick an appropriate crash dump
@@ -238,6 +241,8 @@ type. (Full is quite large, but necessary sometimes for a programmer-type
to load your crash dump into a debugger and begin unwinding exactly what
has happened. Mini is sufficient for your first pass through the process.)
+ You can use `procdump` or `procdump -ma` at this stage instead.
+
1. Note that if you previously installed and then uninstalled other
debugging software, you may need to invoke `drwtsn32 -i` in order to make
Dr Watson your default crash dump tool. This will replace the 'report
@@ -262,6 +267,9 @@ the ThreadsPerChild directive.) The process name is Apache (for 1.3 and
1. Using the {pid} number you noted above, invoke the command
> `drwtsn32 -p {pid}`
+or
+> `procdump {pid}`
+
Voila, you will find in your 'log file path' a `drwtsn32.log` file, and if
you choose to 'append to existing log file', jump through the 'App:'
covener pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/httpd-site.git
The following commit(s) were added to refs/heads/main by this push:
new aedadbe live: procdump and thread apply all bt
aedadbe is described below
commit aedadbefc64987cc599e550ccdad915614aa57d0
Author: Eric Covener <ecovener@us.ibm.com>
AuthorDate: Mon Nov 22 07:55:53 2021 -0500
live: procdump and thread apply all bt
---
content/dev/debugging.md | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/content/dev/debugging.md b/content/dev/debugging.md
index 0372d7b..da7d1a7 100644
--- a/content/dev/debugging.md
+++ b/content/dev/debugging.md
@@ -191,7 +191,13 @@ to display a a live backtrace. For example, on Solaris it looks like
```
Another technique is to use gdb to attach to the running process and then
-using "where" to print the backtrace, as in
+using "thread apply all bt" to print the backtrace, as in:
+
+```
+sudo gdb /path/to/bin/httpd 10623 --batch --eval-command "where" --eval-command "thread apply all bt" --eval-command "detach" --eval-command "quit" | tee gdb-output.txt
+```
+
+Or interactively:
```
% gdb httpd 10623
@@ -205,14 +211,7 @@ using "where" to print the backtrace, as in
/usr/local/apache/src/10623: No such file or directory.
Attaching to program `/usr/local/apache/src/httpd', process 10623
Reading symbols from /usr/lib/libsocket.so.1...done.
- Reading symbols from /usr/lib/libnsl.so.1...done.
- Reading symbols from /usr/lib/libc.so.1...done.
- Reading symbols from /usr/lib/libdl.so.1...done.
- Reading symbols from /usr/lib/libintl.so.1...done.
- Reading symbols from /usr/lib/libmp.so.1...done.
- Reading symbols from /usr/lib/libw.so.1...done.
- Reading symbols from
- /usr/platform/SUNW,Ultra-1/lib/libc_psr.so.1...done.
+ ...
0xef5b68d8 in ()
(gdb) where
#0 0xef5b68d8 in ()
@@ -220,7 +219,9 @@ using "where" to print the backtrace, as in
#2 0x4257c in wait_or_timeout (status=0x0) at http_main.c:2357
#3 0x44318 in standalone_main (argc=392552, argv=0x75800) at...
#4 0x449fc in main (argc=3, argv=0xefffeee4) at http_main.c:4534
- (gdb)
+ (gdb) thread apply all bt
+ (gdb) detach
+ (gdb> quit
```
# Getting a live backtrace on Windows {#backtrace-win}
@@ -231,6 +232,8 @@ usually found.) These.pdb files should unpack alongside the.exe,.dll,.so
binary files they represent, e.g., mod_usertrack.pdb will unpack alongside
mod_usertrack.so.
+1. Optional: Obtain `procdump` from Sysinternals.
+
1. Invoke `drwtsn32` and ensure you are creating a crash dump file, you are
dumping all thread contexts, your log and crash dump paths make sense, and
(depending on the nature of the bug) you pick an appropriate crash dump
@@ -238,6 +241,8 @@ type. (Full is quite large, but necessary sometimes for a programmer-type
to load your crash dump into a debugger and begin unwinding exactly what
has happened. Mini is sufficient for your first pass through the process.)
+ You can use `procdump` or `procdump -ma` at this stage instead.
+
1. Note that if you previously installed and then uninstalled other
debugging software, you may need to invoke `drwtsn32 -i` in order to make
Dr Watson your default crash dump tool. This will replace the 'report
@@ -262,6 +267,9 @@ the ThreadsPerChild directive.) The process name is Apache (for 1.3 and
1. Using the {pid} number you noted above, invoke the command
> `drwtsn32 -p {pid}`
+or
+> `procdump {pid}`
+
Voila, you will find in your 'log file path' a `drwtsn32.log` file, and if
you choose to 'append to existing log file', jump through the 'App:'