Summary:
Backfillers and other housekeeping processes can run so far ahead of the blobstore sync queue that we can't empty it from the healer task as fast as the backfillers can fill it.
Work around this by providing a new mode that background tasks can use to avoid filling the queue if all the blobstores are writing successfully. This has a side-effect of slowing background tasks to the speed of the slowest blobstore, instead of allowing them to run ahead at the speed of the fastest blobstore and relying on the healer ensuring that all blobs are present.
Future diffs will add this mode to appropriate tasks
Reviewed By: ikostia
Differential Revision: D22866818
fbshipit-source-id: a8762528bb3f6f11c0ec63e4a3c8dac08d0b4d8e
Mononoke is a next-generation server for the Mercurial source control
system, meant to scale up to accepting
thousands of commits every hour across millions of files. It is primarily
written in the Rust programming language.
Caveat Emptor
Mononoke is still in early stages of development. We are making it available now because we plan to
start making references to it from our other open source projects.
The version that we provide on GitHub does not build yet.
This is because the code is exported verbatim from an internal repository at Facebook, and
not all of the scaffolding from our internal repository can be easily extracted. The key areas
where we need to shore things up are:
Full support for a standard cargo build.
Open source replacements for Facebook-internal services (blob store, logging etc).
The current goal is to get Mononoke working on Linux. Other Unix-like OSes may
be supported in the future