blob: 970f3407c54972bb88da90962900ddb7b3b7f6ee [file] [log] [blame]
.. _reportingbugs:
.. toctree::
Data to include in bug reports
==============================
Image version and operating environment
---------------------------------------
Please make sure to include the vpp image version and command-line arguments.
.. code-block:: console
$ sudo bash
# vppctl show version verbose cmdline
Version: v18.07-rc0~509-gb9124828
Compiled by: vppuser
Compile host: vppbuild
Compile date: Fri Jul 13 09:05:37 EDT 2018
Compile location: /scratch/vpp-showversion
Compiler: GCC 7.3.0
Current PID: 5211
Command line arguments:
/scratch/vpp-showversion/build-root/install-vpp_debug-native/vpp/bin/vpp
unix
interactive
With respect to the operating environment: if misbehavior involving a
specific VM / container / bare-metal environment is involved, please
describe the environment in detail:
* Linux Distro (e.g. Ubuntu 18.04.2 LTS, CentOS-7, etc.)
* NIC type(s) (ixgbe, i40e, enic, etc. etc.), vhost-user, tuntap
* NUMA configuration if applicable
Please note the CPU architecture (x86_86, aarch64), and hardware platform.
When practicable, please report issues against released software, or
unmodified master/latest software.
"Show" command output
---------------------
Every situation is different. If the issue involves a sequence of
debug CLI command, please enable CLI command logging, and send the
sequence involved. Note that the debug CLI is a developer's tool -
**no warranty express or implied** - and that we may choose not to fix
debug CLI bugs.
Please include "show error" [error counter] output. It's often helpful
to "clear error", send a bit of traffic, then "show error"
particularly when running vpp on noisy networks.
Please include ip4 / ip6 / mpls FIB contents ("show ip fib", "show ip6
fib", "show mpls fib", "show mpls tunnel").
Please include "show hardware", "show interface", and "show interface
address" output
Here is a consolidated set of commands that are generally useful
before/after sending traffic. Before sending traffic:
.. code-block:: console
vppctl clear hardware
vppctl clear interface
vppctl clear error
vppctl clear run
Send some traffic and then issue the following commands.
.. code-block:: console
vppctl show version verbose
vppctl show hardware
vppctl show interface address
vppctl show interface
vppctl show run
vppctl show error
Here are some protocol specific show commands that may also make
sense. Only include those features which have been configured.
.. code-block:: console
vppctl show l2fib
vppctl show bridge-domain
vppctl show ip fib
vppctl show ip neighbors
vppctl show ip6 fib
vppctl show ip6 neighbors
vppctl show mpls fib
vppctl show mpls tunnel
Network Topology
----------------
Please include a crisp description of the network topology, including
L2 / IP / MPLS / segment-routing addressing details. If you expect
folks to reproduce and debug issues, this is a must.
At or above a certain level of topological complexity, it becomes
problematic to reproduce the original setup.
Packet Tracer Output
--------------------
If you capture packet tracer output which seems relevant, please include it.
.. code-block:: console
vppctl trace add dpdk-input 100 # or similar
send-traffic
.. code-block:: console
vppctl show trace
Capturing post-mortem data
==========================
It should go without saying, but anyhow: **please put post-mortem data
in obvious, accessible places.** Time wasted trying to acquire
accounts, credentials, and IP addresses simply delays problem
resolution.
Please remember to add post-mortem data location information to Jira
tickets.
Syslog Output
-------------
The vpp signal handler typically writes a certain amount of data in
/var/log/syslog before exiting. Make sure to check for evidence, e.g
via "grep /usr/bin/vpp /var/log/syslog" or similar.
Binary API Trace
----------------
If the issue involves a sequence of control-plane API messages - even
a very long sequence - please enable control-plane API
tracing. Control-plane API post-mortem traces end up in
/tmp/api_post_mortem.<pid>.
Please remember to put post-mortem binary api traces in accessible
places.
These API traces are especially helpful in cases where the vpp engine
is throwing traffic on the floor, e.g. for want of a default route or
similar.
Make sure to leave the default stanza "... api-trace { on } ... " in
the vpp startup configuration file /etc/vpp/startup.conf, or to
include it in the command line arguments passed by orchestration
software.
Core Files
----------
Production systems, as well as long-running pre-production soak-test
systems, **must** arrange to collect core images. There are various
ways to configure core image capture, including e.g. the Ubuntu
"corekeeper" package. In a pinch, the following very basic sequence
will capture usable vpp core files in /tmp/dumps.
.. code-block:: console
# mkdir -p /tmp/dumps
# sysctl -w debug.exception-trace=1
# sysctl -w kernel.core_pattern="/tmp/dumps/%e-%t"
# ulimit -c unlimited
# echo 2 > /proc/sys/fs/suid_dumpable
If you start VPP from systemd, you also need to edit
/lib/systemd/system/vpp.service and uncomment the "LimitCORE=infinity"
line before restarting VPP.
Vpp core files often appear enormous, but they are invariably
sparse. Gzip compresses them to manageable sizes. A multi-GByte
corefile often compresses to 10-20 Mbytes.
When decompressing a vpp core file, we suggest using "dd" as shown to
create a sparse, uncompressed core file:
.. code-block:: console
$ zcat vpp_core.gz | dd conv=sparse of=vpp_core
Please remember to put compressed core files in accessible places.
Make sure to leave the default stanza "... unix { ... full-coredump
... } ... " in the vpp startup configuration file
/etc/vpp/startup.conf, or to include it in the command line arguments
passed by orchestration software.
Core files from Private Images
==============================
Core files from private images require special handling. If it's
necessary to go that route, copy the **exact** Debian packages (or
RPMs) which correspond to the core file to the same public place as
the core file. A no-excuses-allowed, hard-and-fast requirement.
In particular:
.. code-block:: console
libvppinfra_<version>_<arch>.deb # vppinfra library
libvppinfra-dev_<version>_<arch>.deb # vppinfra library development pkg
vpp_<version>_<arch>.deb # the vpp executable
vpp-dbg_<version>_<arch>.deb # debug symbols
vpp-dev_<version>_<arch>.deb # vpp development pkg
vpp-lib_<version>_<arch>.deb # shared libraries
vpp-plugin-core_<version>_<arch>.deb # core plugins
vpp-plugin-dpdk_<version>_<arch>.deb # dpdk plugin
For reference, please include git commit-ID, branch, and git repo
information [for repos other than gerrit.fd.io] in the Jira ticket.
Note that git commit-ids are crypto sums of the head [latest]
**merged** patch. They say **nothing whatsoever** about local
workspace modifications, branching, or the git repo in question.
Even given a byte-for-byte identical source tree, it's easy to build
dramatically different binary artifacts. All it takes is a different
toolchain version.
On-the-fly Core File Compression
--------------------------------
Depending on operational requirements, it's possible to compress
corefiles as they are generated. Please note that it takes several
seconds' worth of wall-clock time to compress a vpp core file on the
fly, during which all packet processing activities are suspended.
To create compressed core files on the fly, create the following
script, e.g. in /usr/local/bin/compressed_corefiles, owned by root,
executable:
.. code-block:: console
#!/bin/sh
exec /bin/gzip -f - >"/tmp/dumps/core-$1.$2.gz"
Adjust the kernel core file pattern as shown:
.. code-block:: console
sysctl -w kernel.core_pattern="|/usr/local/bin/compressed_corefiles %e %t"
Core File Summary
-----------------
Bottom line: please follow core file handling instructions to the
letter. It's not complicated. Simply copy the exact Debian packages or
RPMs which correspond to core files to accessible locations.
If we go through the setup process only to discover that the image and
core files don't match, it will simply delay resolution of the issue;
to say nothing of irritating the person who just wasted their time.