I was going to send this out to the dev@ list but I'll reply here instead :)
This is a report on the progress we've made recently in the performance working group, specifically highlighting the improvements to master failover performance. Special thanks to Dmitry Zhuk, Michael Park and Yan Xu for the work in this area. I didn't get time to write up something for the libprocess improvements, so I decided to split that out into its own blog post. You can see it on the website here: http://mesos.apache.org/blog/performance-working-group-progress-report/ And I tweeted about it here if you'd like to help share it: https://twitter.com/bmahler/status/940325681312940033 On Mon, Dec 11, 2017 at 12:14 PM, Jie Yu <yujie....@gmail.com> wrote: > This is AWESOME! > > - Jie > > On Mon, Dec 11, 2017 at 11:54 AM, <bmah...@apache.org> wrote: > > > Repository: mesos > > Updated Branches: > > refs/heads/master 83f81b7b2 -> e7244ae1e > > > > > > Added a performance working group December 2017 blog post. > > > > This blog post discusses the master failover performance improvements > > that were made in the past few months. > > > > > > Project: http://git-wip-us.apache.org/repos/asf/mesos/repo > > Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/e7244ae1 > > Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/e7244ae1 > > Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/e7244ae1 > > > > Branch: refs/heads/master > > Commit: e7244ae1eb84a8bfcbe2940107c7f97a53832cf2 > > Parents: 83f81b7 > > Author: Benjamin Mahler <bmah...@apache.org> > > Authored: Mon Dec 11 11:52:43 2017 -0800 > > Committer: Benjamin Mahler <bmah...@apache.org> > > Committed: Mon Dec 11 11:52:43 2017 -0800 > > > > ---------------------------------------------------------------------- > > .../1.3-1.5_master_failover_no_history.png | Bin 0 -> 115884 bytes > > .../1.3-1.5_master_failover_with_history.png | Bin 0 -> 140716 bytes > > ...performance-working-group-progress-report.md | 90 > +++++++++++++++++++ > > 3 files changed, 90 insertions(+) > > ---------------------------------------------------------------------- > > > > > > http://git-wip-us.apache.org/repos/asf/mesos/blob/e7244ae1/ > > docs/images/1.3-1.5_master_failover_no_history.png > > ---------------------------------------------------------------------- > > diff --git a/docs/images/1.3-1.5_master_failover_no_history.png > > b/docs/images/1.3-1.5_master_failover_no_history.png > > new file mode 100644 > > index 0000000..c1dca64 > > Binary files /dev/null and b/docs/images/1.3-1.5_master_ > failover_no_history.png > > differ > > > > http://git-wip-us.apache.org/repos/asf/mesos/blob/e7244ae1/ > > docs/images/1.3-1.5_master_failover_with_history.png > > ---------------------------------------------------------------------- > > diff --git a/docs/images/1.3-1.5_master_failover_with_history.png > > b/docs/images/1.3-1.5_master_failover_with_history.png > > new file mode 100644 > > index 0000000..4f3deec > > Binary files /dev/null and b/docs/images/1.3-1.5_master_ > failover_with_history.png > > differ > > > > http://git-wip-us.apache.org/repos/asf/mesos/blob/e7244ae1/ > > site/source/blog/2017-12-7-performance-working-group-progress-report.md > > ---------------------------------------------------------------------- > > diff --git a/site/source/blog/2017-12-7-performance-working-group- > > progress-report.md b/site/source/blog/2017-12-7- > performance-working-group- > > progress-report.md > > new file mode 100644 > > index 0000000..7e42642 > > --- /dev/null > > +++ b/site/source/blog/2017-12-7-performance-working-group- > > progress-report.md > > @@ -0,0 +1,90 @@ > > +--- > > +layout: post > > +title: December 2017 Performance Working Group Progress Report > > +published: true > > +post_author: > > + display_name: Benjamin Mahler > > + gravatar: fb43656d4d45f940160c3226c53309f5 > > + twitter: bmahler > > +tags: Performance > > +--- > > + > > +**Scalability and performance are key features for Mesos. Some users of > > Mesos already run production clusters that consist of more than 35,000+ > > agents and 100,000+ active tasks.** However, there remains a lot of room > > for improvement across a variety of areas of the system. > > + > > +The performance working group was created in order to focus on some of > > these areas. The group's charter is to improve scalability / throughput / > > latency across the system, and in order to measure our improvements and > > prevent performance regressions we will write benchmarks and automate > them. > > + > > +In the past few months, we've focused on making improvements to the > > following areas: > > + > > +* **Master failover time-to-completion**: Achieved a 450-600% > improvement > > in throughput, which reduces the time-to-completion by 80-85%. > > +* **[Libprocess](https://github.com/apache/mesos/tree/master/ > > 3rdparty/libprocess) message passing throughput**: These improvements > > will be covered in a separate blog post. > > + > > +Before we dive into the master failover improvements, I would like to > > recognize and thank the following contributors: > > + > > +* **Dmitry Zhuk**: for writing *a lot* of patches for improving the > > master failover performance. > > +* **Michael Park**: for reviewing and shipping many of Dmitry's more > > challenging patches. > > +* **Yan Xu**: for writing the master failover benchmark that was the > > basis for measuring the improvements. > > + > > +## Master Failover Time-To-Completion > > + > > +Our first area of focus was to improve the time it takes for a master > > failover to complete, where completion is defined as all of the agents > > successfully re-registering. Mesos is architected to use a centralized > > master with standby masters that participate in a quorum for high > > availability. For scalability reasons, the leading master stores the > state > > of the cluster in-memory. During a master failover, the leading master > > needs to therefore re-build the in-memory state from all of the agents > that > > re-register. During this time, the master is available to process other > > requests, but will be exposing only partial state to API consumers. > > + > > +The rebuilding of the master’s in-memory state can be expensive for > > larger clusters, and so the focus of this effort was to improve the > > efficiency of this. Improvements were made via several areas, and only > the > > highest-impact changes are listed below: > > + > > +### Protobuf 3.5.0 Move Support > > + > > +We upgraded to protobuf 3.5.0 in order to gain move support. When we > > profiled the master, we found that it spent a lot of time copying > protobuf > > messages during agent re-registration. This support allowed us to > eliminate > > copies of protobuf messages while retaining value semantics. > > + > > +### Move Support and Copy Elimination in Libprocess `dispatch` / `defer` > > / `install` > > + > > +Libprocess provides several primitives for message passing: > > + > > +* `dispatch`: Provides the ability to post a messages to a local > `Process` > > +* `defer`: Provides a deferred `dispatch`. i.e. a function object that > > when invoked will issue a `dispatch`. > > +* `install`: Installs a handler for receiving a protobuf message. > > + > > +These primitives did not have move support, as they were originally > added > > prior to the addition of C++11 support to the code-base. In order to > > eliminate copies, we enhanced these primitives to support moving > arguments > > in and out. > > + > > +This required introducing a new C++ utility, because `defer` takes on > the > > same API as `std::bind` (e.g., placeholders). Specifically, the function > > object returned by `std::bind` does not move the bound arguments into the > > stored callable. In order to enable this, `defer` now uses a utility we > > introduced called `lambda::partial` rather than `std::bind`. > > `lambda::partial` performs partial function application similar to > > `std::bind` except the returned function object moves the bound arguments > > into the stored callable if the invocation is performed on an r-value > > function object. > > + > > +### Copy Elimination in the Master > > + > > +With these previous enhancements in place, we were able to eliminate > many > > of the expensive copies of protobuf messages performed by the master. > > + > > +### Benchmark and Results > > + > > +We wrote a synthetic benchmark to simulate a master failover. This > > benchmark prepares all the messages that would be sent to the master by > the > > agents that need to re-register: > > + > > +* The benchmark uses synthetic agents in that they are just an actor > that > > knows how to re-register with the master. > > +* Each "agent" will send a configurable number of active and completed > > tasks belonging to a configurable number of active and completed > frameworks. > > +* Each task has 10 small labels to introduce metadata overhead. > > + > > +The benchmark has a few caveats: > > + > > +* It does not use executors (this would show improved results over what > > is shown below, but for simplicity the benchmark omits them) > > +* It uses local message passing, whereas a real cluster would be passing > > messages over HTTP. > > +* It uses a quorum size of 1, so writes to the master’s registry occur > > only on single local log replica. > > +* The synthetic agents do not retry their re-registration, whereas > > typically agents will retry with a backoff. > > + > > +This was tested on a 2015 Macbook Pro with 2.8 GHz Intel Core i7 > > processor. Mesos was configured using: `Apple LLVM version 9.0.0 > > (clang-900.0.38)`, with `-O2` enabled in 1.5.0. > > + > > +The first results represent a cluster with 10 active tasks per agent > > across 5 frameworks, with no completed tasks. The results from 1,000 - > > 40,000 agents with 10,000 - 400,000 active tasks: > > + > > + > > + > > +There was a reduction in the time-to-completion of ~80% due to a > 450-500% > > improvement in throughput across 1.3.0 to 1.5.0. > > + > > +The second results add task history: each agent also now contains 100 > > completed tasks across 5 completed frameworks. The results from 1,000 - > > 40,000 agents with 10,000 - 400,000 active tasks and 100,000 - 4,000,000 > > completed tasks are shown below: > > + > > + > > + > > +This represents a reduction in time-to-completion of ~85% due to a > > 550-700% improvement in throughput across 1.3.0 to 1.5.0. > > + > > +## Performance Working Group Roadmap > > + > > +We're currently targeting the following areas for improvements: > > + > > +* **Performance of the v1 API**: Currently the v1 API can be > > significantly slower than the v0 API. We would like to reach parity, and > > ideally surpass the performance of the v0 API. > > + * **[Libprocess](https://github.com/apache/mesos/tree/master/ > > 3rdparty/libprocess) HTTP performance**: This will be undertaken as part > > of improving the v1 API performance, since it is HTTP-based. > > +* **Master state API performance**: Currently, API queries of the > > master's state are serviced by the same master actor that processes all > of > > the messages from schedulers and agents. Since the query processing can > > block the master from processing other events, users need to be careful > not > > to query the master excessively. In practice, the master gets queried > quite > > heavily due to the presence of several tools that rely on the master's > > state (e.g. DNS tooling, UIs, CLIs, etc) and so this is a critical > problem > > for users. This effort will leverage the state streaming API to stream > the > > state to a different actor that can serve the state API requests. This > will > > ensure that expensive state queries do not affect the master's ability to > > process events. > > + > > +If you are a user and would like to suggest some areas for performance > > improvement, please let us know by emailing <d...@apache.mesos.org>. > > > > >
