Phase stats sync assertion error

Alex Rousskov rousskov at
Tue May 9 19:22:53 UTC 2017

On 05/08/2017 11:30 PM, William Law wrote:

> Running polygraph 4.9.0 on CentOS 6.8 (compiled from tarball).  While the
> simple tests, etc seem to run ok, a more gung-ho configuration that ran ok
> on an earlier version doesn't want to play ball with the new configuration.
> I'm getting random assertion fails on both polygraph-client and
> polygraph-server:
> assertion failed: 'false'

Is it possible that you have multiple tests running concurrently?  For
example, perhaps your test setup does not always kill servers (or
clients) from the old test and they prevent some servers from the new
test starting without you noticing? You can work around this problem by
disabling phase synchronization, but that is not a proper fix, of course.

Is it possible that you have more than ~30 Polygraph processes
participating in a test? There is a hard-coded limit (that we should
remove) in phase synchronization code. You can work around this problem
by increasing the limit (search for 37 in src/runtime/
and recompiling Polygraph. Please let us know if that helps!

Overlapping tests and more than ~30 processes are the known cases that
may cause those assertions in your Polygraph version.

> Example client command:
> polygraph-client --worker 61 ...
> Server command:
> polygraph-server --worker 40 ...

Why are you using --worker if you are not running SMP tests?

Thank you,


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