The unixctl library had used the vde2 management protocol since the
early days of Open vSwitch. As Open vSwitch has matured, several
Python daemons have been added to the code base which would benefit
from a unixctl implementations. Instead of implementing the old
unixctl protocol in Python, this patch changes unixctl to use JSON
RPC for which we already have an implementation in both Python and
C. Future patches will need to implement a unixctl library in
Python on top of JSON RPC.
Signed-off-by: Ethan Jackson <ethan@nicira.com>
Otherwise coverage log messages will eventually get rotated out of the
system logs and never reappear (before restarting a given daemon).
Bug #1452.
Signed-off-by: Ben Pfaff <blp@nicira.com>
The protocol used by ovs-appctl has a long-standing bug that there
is no way to distinguish "ovs-appctl a b c" from "ovs-appctl 'a b c'".
This isn't a big deal because none of the current commands really
want to accept arguments that include spaces, but it's kind of a silly
limitation.
At the same time, the internal API is awkward because every user is
stuck doing its own argument parsing, which is no fun.
This commit fixes both problems, by adding shell-like quoting to the
protocol and modifying the internal API from one that passes a string
to one that passes in an array of pre-parsed strings. Command
implementations may now specify how many arguments they expect. This
simplifies some command implementations significantly.
Signed-off-by: Ben Pfaff <blp@nicira.com>
Until now, the collection of coverage counters supported by a given OVS
program was not specific to that program. That means that, for example,
even though ovs-dpctl does not have anything to do with mac_learning, it
still has a coverage counter for it. This is confusing, at best.
This commit fixes the problem on some systems, in particular on ones that
use GCC and the GNU linker. It uses the feature of the GNU linker
described in its manual as:
If an orphaned section's name is representable as a C identifier then
the linker will automatically see PROVIDE two symbols: __start_SECNAME
and __end_SECNAME, where SECNAME is the name of the section. These
indicate the start address and end address of the orphaned section
respectively.
Systems that don't support these features retain the earlier behavior.
This commit also fixes the annoyance that files that include coverage
counters must be listed on COVERAGE_FILES in lib/automake.mk.
This commit also fixes the annoyance that modifying any source file that
includes a coverage counter caused all programs that link against
libopenvswitch.a to relink, even programs that the source file was not
linked into. For example, modifying ofproto/ofproto.c (which includes
coverage counters) caused tests/test-aes128 to relink, even though
test-aes128 does not link again ofproto.o.
Adding a macro to define the vlog module in use adds a level of
indirection, which makes it easier to change how the vlog module must be
defined. A followup commit needs to do that, so getting these widespread
changes out of the way first should make that commit easier to review.
By default, many OVS processes keep track of their time through a poll
loop. If it takes an unusually long time (measured as some distance
from the mean), the processes will log stats it has been keeping about
coverage. It was doing this at level WARN.
On Xen systems, syslog messages written at level INFO and higher are
written to /var/log/messages synchronously. This would mean that there
would be dire messages that it took a few dozen milliseconds to go
through the loop, meanwhile, it would take up to 6(!) seconds writing
those. Meanwhile, the process would do no other processing, which could
be quite serious in the case of a process such as ovs-vswitchd.
This problem was somewhat masked because the time used by this logging
was not used in the calculations for determining how long it was taking
to get through the loop.
This commit lowers the default log level for those coverage messages to
INFO. On Xen systems, it raises the default level at which messages are
written to syslog to WARN.
Diagnosed and fixed with the help of Ian Campbell.
When providing the ability to force coverage printouts to occur, some
code was moved around that allowed the "hash" variable to be used
unitialized. This fixes that.
Thanks to Ben for pointing out the problem.
Bug #1577
Previously, there was no way to induce coverage information to be
displayed; it would only print when the system noticed unusual delays
between polling intervals. Now, production of coverage logs can be
forced with "coverage/log" command in ovs-appctl. Coverage counters may
be reset with "coverage/clear".
