Loki Storage
Loki needs to store two different types of data: chunks and indexes.
Loki receives logs in separate streams, where each stream is uniquely identifiedby its tenant ID and its set of labels. As log entries from a stream arrive,they are GZipped as “chunks” and saved in the chunks store. See chunkformat for how chunks are stored internally.
The index stores each stream’s label set and links them to the individualchunks.
Refer to Loki’s configuration for details onhow to configure the storage and the index.
For more information:
Supported Stores
The following are supported for the index:
- Amazon DynamoDB
- Google Bigtable
- Apache Cassandra
- BoltDB (doesn’t work when clustering Loki)
The following are supported for the chunks:
- Amazon DynamoDB
- Google Bigtable
- Apache Cassandra
- Amazon S3
- Google Cloud Storage
- Filesystem (doesn’t work when clustering Loki)
Cloud Storage Permissions
S3
When using S3 as object storage, the following permissions are needed:
s3:ListBucket
s3:PutObject
s3:GetObject
DynamoDB
When using DynamoDB for the index, the following permissions are needed:
dynamodb:BatchGetItem
dynamodb:BatchWriteItem
dynamodb:DeleteItem
dynamodb:DescribeTable
dynamodb:GetItem
dynamodb:ListTagsOfResource
dynamodb:PutItem
dynamodb:Query
dynamodb:TagResource
dynamodb:UntagResource
dynamodb:UpdateItem
dynamodb:UpdateTable
Chunk Format
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| | |
| MagicNumber(4b) | version(1b) |
| | |
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| block-1 bytes | checksum (4b) |
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| block-2 bytes | checksum (4b) |
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| block-n bytes | checksum (4b) |
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| #blocks (uvarint) |
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| #entries(uvarint) | mint, maxt (varint) | offset, len (uvarint) |
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| #entries(uvarint) | mint, maxt (varint) | offset, len (uvarint) |
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| #entries(uvarint) | mint, maxt (varint) | offset, len (uvarint) |
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| #entries(uvarint) | mint, maxt (varint) | offset, len (uvarint) |
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| checksum(from #blocks) |
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| metasOffset - offset to the point with #blocks |
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