8 Commits (e4364b75b153981db0ea5aa41f681795e791935c)

Author	SHA1	Message	Date
Mike Lang	bf08aa29b8	parse_segment_path: Use datetime.strptime instead of dateutil.parser ... strptime is much faster but can't handle as varied formats. But in this case we fully control the format, so there's no reason not to use it. Profiling suggests we spend about 80% of our time in get_best_segments just parsing dates, so this is a signifigant performance gain.	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	8fe2fec958	common: convert from module to package	6 years ago
Mike Lang	d90f01b8ce	common: Create general function for timing things, and use it to time get_best_segments ... The function is quite customizable and therefore quite complex, but it allows us to easily annotate a function to be timed with labels based on input and output, as well as normalize results based on amount of work done to get a better picture of the actual amount of time taken per unit of work. This will help us monitor for performance issues.	6 years ago
Mike Lang	b0ded641c3	Add a logging handler which counts logs for prometheus stats ... This isn't as good as having a full centralised logging system, but should suffice to know if anything funny is happening.	6 years ago
Mike Lang	d7641aecf5	common: Fix bugs and issues with bustime utils	6 years ago
Mike Lang	048277b003	common: Basic config and bustime code	6 years ago
Mike Lang	a361ab7a63	Add a common package for common bits in multiple components	6 years ago