[MESOS-7713] Optimize number of copies made in dispatch/defer mechanism

• Type: Task
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.0, 1.2.1, 1.3.0
• Fix Version/s: 1.4.0
• Component/s: libprocess
• Target Version/s: 1.4.0
• Sprint: Mesosphere Sprint 60, Mesosphere Sprint 61
• Story Points: 3
• Assignee: Dmitry Zhuk
• Reporter: Dmitry Zhuk
• Shepherd: Michael Park
• Created: 22/Jun/17 20:24
• Updated: 08/Aug/17 23:00
• Resolved: 08/Aug/17 23:00

Description

Profiling agents reregistration for a large cluster shows, that many CPU cycles are spent on copying protobuf objects. This is partially due to copies made by a code like this:

future.then(defer(self(), &Process::method, param);

param could be copied 8-10 times before it reaches method. Specifically, reregisterSlave accepts vectors of rather complex objects, which are passed to defer.
Currently there are some places in defer, dispatch and Future code, which could use std::move and std::forward to evade some of the copies.

Issue Links

• relates to: MESOS-7688 Improve master failover performance by reducing unnecessary agent retries.