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Ian Wienand2bbc9bb2019-02-11 12:25:38 +11001=====================
2System-wide debugging
3=====================
4
5A lot can go wrong during a devstack run, and there are a few inbuilt
6tools to help you.
7
8dstat
9-----
10
11Enable the ``dstat`` service to produce performance logs during the
12devstack run. These will be logged to the journal and also as a CSV
13file.
14
15memory_tracker
16--------------
17
18The ``memory_tracker`` service periodically monitors RAM usage and
19provides consumption output when available memory is seen to be
20falling (i.e. processes are consuming memory). It also provides
21output showing locked (unswappable) memory.
22
23tcpdump
24-------
25
26Enable the ``tcpdump`` service to run a background tcpdump. You must
27set the ``TCPDUMP_ARGS`` variable to something suitable (there is no
28default). For example, to trace iSCSI communication during a job in
29the OpenStack gate and copy the result into the log output, you might
30use:
31
32.. code-block:: yaml
33
34 job:
35 name: devstack-job
36 parent: devstack
37 vars:
38 devstack_services:
39 tcpdump: true
40 devstack_localrc:
41 TCPDUMP_ARGS: "-i any tcp port 3260"
42 zuul_copy_output:
43 '{{ devstack_log_dir }}/tcpdump.pcap': logs
44
45
46