* Factor out starting Ray processes.
* Detect flags through environment variables.
* Return ProcessInfo from start_ray_process.
* Print valgrind errors at exit.
* Test valgrind in travis.
* Some valgrind fixes.
* Undo raylet monitor change.
* Only test plasma store in valgrind.
* Refactor code about ray.ObjectID.
* remove from_random and use nil_id instead of constructor
* remove id() in hash
* Lint and fix
* Change driver id to ObjectID
* Replace binary_to_hex(ObjectID.id()) to ObjectID.hex()
* Push a warning to all users when large number of workers have been started.
* Add test.
* Fix bug.
* Give warning when worker starts instead of when worker registers.
* Fix
* Fix tests
* Limit Redis max memory to 10GB/shard by default.
* Update stress tests.
* Reorganize
* Update
* Add minimum cap size for object store and redis.
* Small test update.
## What do these changes do?
1. Separate the log related code to logger.py from services.py.
2. Allow users to modify logging formatter in `ray start`.
## Related issue number
https://github.com/ray-project/ray/pull/2664
* Fix documentation indentation.
* Add error table to GCS and push error messages through node manager.
* Add type to error data.
* Linting
* Fix failure_test bug.
* Linting.
* Enable one more test.
* Attempt to fix doc building.
* Restructuring
* Fixes
* More fixes.
* Move current_time_ms function into util.h.
* AWS: support multiple availability zones (fix#2177)
* Bugfix: [] rather than ()
* Test config
* Test config tweaks
* Remove test config
* Formatting fixes
* Update YAML config
* Print warning when defining very large remote function or actor.
* Add weak test.
* Check that warnings appear in test.
* Make wait_for_errors actually fail in failure_test.py.
* Use constants for error types.
* Fix
* some autoscaling config tweaks
* Sun Jan 14 13:56:55 PST 2018
* Mon Jan 15 14:21:09 PST 2018
* increase backoff
* Mon Jan 15 14:40:47 PST 2018
* check boto version
This adds (experimental) auto-scaling support for Ray clusters based on GCS load metrics. The auto-scaling algorithm is as follows:
Based on current (instantaneous) load information, we compute the approximate number of "used workers". This is based on the bottleneck resource, e.g. if 8/8 GPUs are used in a 8-node cluster but all the CPUs are idle, the number of used nodes is still counted as 8. This number can also be fractional.
We scale that number by 1 / target_utilization_fraction and round up to determine the target cluster size (subject to the max_workers constraint). The autoscaler control loop takes care of launching new nodes until the target cluster size is met.
When a node is idle for more than idle_timeout_minutes, we remove it from the cluster if that would not drop the cluster size below min_workers.
Note that we'll need to update the wheel in the example yaml file after this PR is merged.