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diff --git a/docs/contributing/reportingissues/index.rst b/docs/contributing/reportingissues/index.rst new file mode 100644 index 00000000000..b16a2a915a8 --- /dev/null +++ b/docs/contributing/reportingissues/index.rst @@ -0,0 +1,23 @@ +.. _reportingissues: + +Reporting Bugs +============== + +Although every situation is different, this section describes how to +collect data which will help make efficient use of everyone's time +when dealing with vpp bugs. + +Before you press the Jira button to create a bug report - or email +vpp-dev@lists.fd.io - please ask yourself whether there's enough +information for someone else to understand and to reproduce the issue +given a reasonable amount of effort. **Unicast emails to maintainers, +committers, and the project PTL are strongly discouraged.** + +A good strategy for clear-cut bugs: file a detailed Jira ticket, and +then send a short description of the issue to vpp-dev@lists.fd.io, +perhaps from the Jira ticket description. It's fine to send email to +vpp-dev@lists.fd.io to ask a few questions **before** filing Jira tickets. + +.. toctree:: + + reportingissues diff --git a/docs/contributing/reportingissues/reportingissues.rst b/docs/contributing/reportingissues/reportingissues.rst new file mode 100644 index 00000000000..970f3407c54 --- /dev/null +++ b/docs/contributing/reportingissues/reportingissues.rst @@ -0,0 +1,266 @@ +.. _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. |