Repository: mesos Updated Branches: refs/heads/master 05c608f80 -> bcf686b2b
Added high-level description to persistent volume docs. Review: https://reviews.apache.org/r/38325 Project: http://git-wip-us.apache.org/repos/asf/mesos/repo Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/bcf686b2 Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/bcf686b2 Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/bcf686b2 Branch: refs/heads/master Commit: bcf686b2bb1ede77602f0c6b3667c475c80a7967 Parents: 05c608f Author: Neil Conway <[email protected]> Authored: Fri Sep 11 16:10:48 2015 -0700 Committer: Jie Yu <[email protected]> Committed: Fri Sep 11 16:11:21 2015 -0700 ---------------------------------------------------------------------- docs/persistent-volume.md | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/mesos/blob/bcf686b2/docs/persistent-volume.md ---------------------------------------------------------------------- diff --git a/docs/persistent-volume.md b/docs/persistent-volume.md index b5dd6d8..0f66442 100644 --- a/docs/persistent-volume.md +++ b/docs/persistent-volume.md @@ -4,10 +4,16 @@ layout: documentation # Persistent Volume -Mesos provides a mechanism to create a persistent volume from disk resources. -This enables stateful services such as HDFS and Cassandra to store their data -within Mesos rather than having to resort to network-mounted EBS volumes that -needs to be placed in a well-known location. +Mesos provides a mechanism to create a persistent volume from disk +resources. When launching a task, you can create a volume that exists outside +the task's sandbox and will persist on the node even after the task dies or +completes. When the task exits, its resources -- including the persistent volume +-- can be offered back to the framework, so that the framework can launch the +same task again, launch a recovery task, or launch a new task that consumes the +previous task's output as its input. Persistent volumes enable stateful services +such as HDFS and Cassandra to store their data within Mesos rather than having +to resort to workarounds (e.g., writing task state to a distributed filesystem +that is mounted at a well-known location outside the task's sandbox). Persistent volumes can only be created from __reserved__ disk resources, whether it be statically reserved or dynamically reserved. A dynamically reserved @@ -16,9 +22,8 @@ the volume. These rules exist to limit the accidental mistakes such as: a persistent volume containing sensitive data being offered to other frameworks in the cluster. -Please refer to the -[Reservation](reservation.md) documentation for details regarding reservation -mechanisms available in Mesos. +Please refer to the [Reservation](reservation.md) documentation for details +regarding reservation mechanisms available in Mesos. Persistent volumes can be created by __operators__ and authorized __frameworks__. We require a `principal` from the operator or framework in order
