Keepstore provides access to underlying storage for reading and writing content-addressed blocks, with enforcement of Arvados permissions. Keepstore supports a variety of cloud object storage and POSIX filesystems for its backing store.
+h3. Plan your storage layout
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+In the steps below, you will configure a number of backend storage volumes (like local filesystems and S3 buckets) and specify which keepstore servers have read-only and read-write access to which volumes.
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+It is possible to configure arbitrary server/volume layouts. However, in order to provide good performance and efficient use of storage resources, we strongly recommend using one of the following layouts:
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+# Each volume is writable by exactly one server, and optionally readable by one or more other servers. The total capacity of all writable volumes is the same for each server.
+# Each volume is writable by all servers. Each volume has enough built-in redundancy to satisfy your requirements, i.e., you do not need Arvados to mirror data across multiple volumes.
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We recommend starting off with two Keepstore servers. Exact server specifications will be site and workload specific, but in general keepstore will be I/O bound and should be set up to maximize aggregate bandwidth with compute nodes. To increase capacity (either space or throughput) it is straightforward to add additional servers, or (in cloud environments) to increase the machine size of the existing servers.
By convention, we use the following hostname pattern:
On its own, a keepstore server never deletes data. The "keep-balance":install-keep-balance.html service determines which blocks are candidates for deletion and instructs the keepstore to move those blocks to the trash.
-When a block is newly written, it is protected from deletion for the duration in @BlobSignatureTTL@. During this time, it cannot be trashed.
+When a block is newly written, it is protected from deletion for the duration in @BlobSigningTTL@. During this time, it cannot be trashed or deleted.
-If keep-balance instructs keepstore to trash a block which is older than @BlobSignatureTTL@, and @EnableDelete@ is true, the block will be moved to "trash". A block which is in the trash is no longer accessible by read requests, but has not yet been permanently deleted. Blocks which are in the trash may be recovered using the "untrash" API endpoint. Blocks are permanently deleted after they have been in the trash for the duration in @TrashLifetime@.
+If keep-balance instructs keepstore to trash a block which is older than @BlobSigningTTL@, and @BlobTrashLifetime@ is non-zero, the block will be moved to "trash". A block which is in the trash is no longer accessible by read requests, but has not yet been permanently deleted. Blocks which are in the trash may be recovered using the "untrash" API endpoint. Blocks are permanently deleted after they have been in the trash for the duration in @BlobTrashLifetime@.
-Keep-balance is also responsible for balancing the distribution of blocks across keepstore servers by asking servers to pull blocks from other servers (as determined by their "storage class":{{site.baseurl}}/admin/storage-classes.html and "rendezvous hashing order":{{site.baseurl}}/api/storage.html). Pulling a block makes a copy. If a block is overreplicated (i.e. there are excess copies) after pulling, it will be subsequently trashed on the original server.
+Keep-balance is also responsible for balancing the distribution of blocks across keepstore servers by asking servers to pull blocks from other servers (as determined by their "storage class":{{site.baseurl}}/admin/storage-classes.html and "rendezvous hashing order":{{site.baseurl}}/api/storage.html). Pulling a block makes a copy. If a block is overreplicated (i.e. there are excess copies) after pulling, it will be subsequently trashed and deleted on the original server, subject to @BlobTrash@ and @BlobTrashLifetime@ settings.
h3. Configure storage volumes
projects / arvados.git / blobdiff