wubloader

Author	SHA1	Message	Date
Mike Lang	bcdb268ce8	Also need to replace locks on the counter float values to prevent deadlocks See comment for full details	6 years ago
Mike Lang	10cca18922	Fix a deadlock due to signal interactions with prometheus client The prometheus client uses a threading.Lock() to prevent shared access to certain metric state. This lock is taken as part of doing collection, as well as during metric.labels(). We hit a deadlock where our stack sampler signal arrived during a collection, when the lock was held. This meant that flamegraph.labels() blocked forever, and the lock was never released, hanging all metrics collection. Our solution is a hack, which is to reach into the internals of our metric object and replace its lock with a dummy one. This is reasonably safe, but only as long as the prometheus_client internal structure doesn't change signfigiantly.	6 years ago
Mike Lang	b9c2921242	common.stats: Add a stacksampler that records sampled stacks to prometheus This can then be used to generate flamegraphs	6 years ago
Mike Lang	6f84a23ba6	common: Split stats-related stuff into its own module We still import them into __init__.py so they're accessible externally just the same	6 years ago