Merge pull request #1834 from dmcgowan/v1.0.0-rc.0-notes

Add release notes for v1.0.0-rc.0

releases/v1.0.0-rc.0.toml

@@ -0,0 +1,81 @@
+# commit to be tagged for new release
+commit = "HEAD"
+
+project_name = "containerd"
+github_repo = "containerd/containerd"
+
+# previous release
+previous = "v1.0.0-rc.0"
+
+pre_release = true
+
+preface = """\
+The final 1.0 release stretch has been reached after 7 alphas and 4 betas full
+of stability fixes, hardening, and API improvements. This release candidate
+continues that pattern in including stability fixes, usability improvements and
+performance optimizations.
+
+As part of the preparation for supporting the release of Containerd 1.0, the
+governance model has been updated. The same as in previous versions, the day to
+day management of the project is taken care of by the maintainers. The roles
+of chief maintainer and BDFL have been removed and a technical steering
+committee has been added as an escalation point when consensus cannot be reached
+among maintainers. See https://github.com/moby/tsc."""
+
+# notable prs to include in the release notes, 1234 is the pr number
+[notes]
+
+  [notes.ctr]
+  title= "Shim Memory Improvements"
+  description = """\
+The shim memory usage has been identified as a key component to optimize. The
+shim gets run for every container making memory usage multiplied by the
+number of containers on a machine, requiring lower memory usage in order to
+increase density.
+
+In profiling the memory usage of the shim, it was discovered that the HTTP2
+and GRPC stacks were accounting for a majority of the usage. Since the RPC
+requests to the shim are fairly simple and there is no need for handling many
+clients, a simpler protocol is now used with much less overhead. In order to
+avoid changing the client or server code, ttrpc is used to generate code
+similar to GRPC using the same protocol definitions, but using the lighter
+weight protocol. This had the effect of drastically reducing the memory
+usage of the shim.
+
+Memory improvements over beta 2...
+```
+  RSS CMD
+ 3644 containerd-shim -namespace default -workdir /var/lib/containerd/io.containerd.runtime.v1.linux/default/test10 -address /run/containerd/containerd.sock -containerd-binary /usr/local/bin/containerd -debug
+15320 docker-containerd-shim --namespace moby --workdir /var/lib/docker/containerd/daemon/io.containerd.runtime.v1.linux/moby/ffa219303c1419b179393a1123f176bb4268337432b0ca7945bc7ac66db73cad --address /var/run/docker/containerd/docker-containerd.sock --runtime-root /var/run/docker/
+```
+
+See [ttrpc repository](https://github.com/stevvooe/ttrpc) for implementation."""
+
+  [notes.gc]
+  title= "Garbage Collector Improvements"
+  description = """\
+Garbage collection is now scheduled by a background process which watches
+changes and tracks the amount of time garbage collection is taking. It is able
+to use that information to schedule garbage collection based on configuration
+options. The default configuration option aims to limit the amount of time the
+metadata store is locked for garbage collection to 20ms of every second.
+
+Additionally image removal now has an option to synchronously cleanup all
+referenced resources (such as snapshots). This option immediately schedules a
+garbage collection and waits for it to complete before returning to the client.
+Since the time to remove a snapshot depends on the size of the snapshot, the
+time to synchronously remove an image cannot be consistent. For faster and
+more consistent removals, images should be deleted asynchronously whenever
+possible. Asynchronous remains the default."""
+
+
+[breaking]
+	[breaking.api]
+	pr = 1797
+	description = "The snapshots GRPC service was renamed from snapshot."
+
+	[breaking.shim]
+	pr = 1767
+	description = """\
+The shim protocol has changed to use ttrpc. The new protocol does not use
+http2 and is not compatible with previous shim versions using grpc."""