Repository: mesos Updated Branches: refs/heads/master a36c1c962 -> c0b8a0672
Improved Multiple Disk documentation. Review: https://reviews.apache.org/r/43633/ Project: http://git-wip-us.apache.org/repos/asf/mesos/repo Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/c0b8a067 Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/c0b8a067 Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/c0b8a067 Branch: refs/heads/master Commit: c0b8a0672023fc32fe13230f9b003bf36f20196e Parents: a36c1c9 Author: Joerg Schad <[email protected]> Authored: Tue Feb 16 18:02:48 2016 -0500 Committer: Joris Van Remoortere <[email protected]> Committed: Tue Feb 16 18:02:58 2016 -0500 ---------------------------------------------------------------------- docs/multiple-disk.md | 100 ++++++++++++++++++++--------------------- docs/persistent-volume.md | 2 +- 2 files changed, 49 insertions(+), 53 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/mesos/blob/c0b8a067/docs/multiple-disk.md ---------------------------------------------------------------------- diff --git a/docs/multiple-disk.md b/docs/multiple-disk.md index 4fc5327..ab2e7e8 100644 --- a/docs/multiple-disk.md +++ b/docs/multiple-disk.md @@ -28,18 +28,16 @@ A `Root` disk is the basic disk resource in Mesos. It usually maps to the storage on the main operating system drive that the operator has presented to the agent. Data is mapped into the `work_dir` of the agent. -``` -{ - "resources" : [ - { - "name" : "disk", - "type" : "SCALAR", - "scalar" : { "value" : 2048 }, - "role" : <framework_role> - } - ] -} -``` + { + "resources" : [ + { + "name" : "disk", + "type" : "SCALAR", + "scalar" : { "value" : 2048 }, + "role" : <framework_role> + } + ] + } #### `Path` disks @@ -51,28 +49,26 @@ Operators can present extra disks on their agents as `Path` disks simply by creating a directory and making that the `root` of the `Path` in `DiskInfo`'s `source`. -`Path` disks are also useful for mocking up a multiple-disk environment by +`Path` disks are also useful for mocking up a multiple disk environment by creating some directories on the operating system drive. This should only be done in a testing or staging environment. -``` -{ - "resources" : [ - { - "name" : "disk", - "type" : "SCALAR", - "scalar" : { "value" : 2048 }, - "role" : <framework_role>, - "disk" : { - "source" : { - "type" : "PATH", - "path" : { "root" : "/mnt/data" } + { + "resources" : [ + { + "name" : "disk", + "type" : "SCALAR", + "scalar" : { "value" : 2048 }, + "role" : <framework_role>, + "disk" : { + "source" : { + "type" : "PATH", + "path" : { "root" : "/mnt/data" } + } + } + } + ] } - } - } - ] -} -``` #### `Mount` disks @@ -92,26 +88,24 @@ Aside from the performance advantages of `Mount` disks, applications running on them should be able to rely on disk errors when they attempt to exceed the capacity of the volume. This holds true as long as the file system in use correctly propagates these errors. Due to this expectation, the `posix/disk` -quota enforcement is disabled for `Mount` disks. - -``` -{ - "resources" : [ - { - "name" : "disk", - "type" : "SCALAR", - "scalar" : { "value" : 2048 }, - "role" : <framework_role>, - "disk" : { - "source" : { - "type" : "MOUNT", - "mount" : { "root" : "/mnt/data" } +isolation is disabled for `Mount` disks. + + { + "resources" : [ + { + "name" : "disk", + "type" : "SCALAR", + "scalar" : { "value" : 2048 }, + "role" : <framework_role>, + "disk" : { + "source" : { + "type" : "MOUNT", + "mount" : { "root" : "/mnt/data" } + } + } + } + ] } - } - } - ] -} -``` #### `Block` disks @@ -126,7 +120,7 @@ destroyed. It may do so in the future; however, the expectation is currently upon the framework, executor, and application to delete their data before destroying their persistent volumes. This is strongly encouraged for both security and ensuring that future users of the underlying disk resource are not -penalized for prior consumption of the disk capacity. +penalized due to prior consumption of the disk capacity. ### Implementation @@ -134,8 +128,10 @@ A `Path` disk will have sub-directories created within the `root` which will be used to differentiate the different volumes that are created on it. A `Mount` disk will __not__ have sub-directories created, allowing applications -to use the full file system mounted on the device. This provides operators a -construct through which to enable data ingestion. +to use the full file system mounted on the device. This construct allows Mesos +tasks to access volumes that contain pre-existing directory structures. This can +be useful to simplify ingesting data such as a pre-existing Postgres database or +HDFS data directory. Operators should be aware of these distinctions when inspecting or cleaning up remnant data. \ No newline at end of file http://git-wip-us.apache.org/repos/asf/mesos/blob/c0b8a067/docs/persistent-volume.md ---------------------------------------------------------------------- diff --git a/docs/persistent-volume.md b/docs/persistent-volume.md index 7288540..2a794a5 100644 --- a/docs/persistent-volume.md +++ b/docs/persistent-volume.md @@ -26,7 +26,7 @@ Please refer to the [Reservation](reservation.md) documentation for details regarding reservation mechanisms available in Mesos. Persistent volumes can also be created on isolated and auxiliary disks by -reserving [Multiple Disk resources](multiple-disk.md). +reserving [multiple disk resources](multiple-disk.md). Persistent volumes can be created by __operators__ and authorized __frameworks__. We require a `principal` from the operator or framework in order
