Object Caching

Tigris behaves like a Content Delivery Network (CDN) with no work on your part. Unlike traditional CDNs, though, it handles dynamic data in a way that provides strong guarantees around freshness of data.

Tigris transparently caches the objects close to the user to provide low-latency access. The region choosen for caching the objects depends on the request pattern from the users. Objects stored in San Jose but requested frequently from Sydney will result in getting cached in the Sydney region. Caching is provided through a distributed global caching layer with cache nodes deployed in regions globally. This ensures that user requests can be served from the region closest to the user.

Object caching requires no configuration and is enabled by default on all buckets.

Cache Headers

By default, Tigris honors the cache headers set by the user when writing the object, and returns those headers as part of the response when the object is fetched. This allows the user to control the caching behavior of the object.

Public Buckets

Tigris sets default cache header for public buckets for static assets if no cache headers are provided by the user. The default cache header is set to Cache-Control: public, max-age=3600. This applies to the following static assets:

Category	MIME types
Web assets	text/css text/ecmascript text/javascript application/javascript
Fonts	Any Content-Type matching font/*
Images	Any Content-Type matching image/*
Videos	Any Content-Type matching video/*
Audio	Any Content-Type matching audio/*
Formatted document types	application/pdf and application/postscript

Caching on PUT (Eager Caching)

In addition to the default caching behavior, Tigris provides a way to eagerly cache objects on write. This is useful when you know that an object will be frequently accessed from a region different from the region where the object is written.

note

We have found Cache-on-Read to be sufficient for most of the use cases and the most cost-effective, but Cache-on-Write is available for use cases that need it.

The AWS CLI and SDKs can be used to enable eager caching on write. The following example shows how to enable eager caching on write using the AWS CLI

aws s3api put-bucket-accelerate-configuration \
	--bucket foo-bucket \
	--accelerate-configuration Status=Enabled

Caching on List (Eager Caching)

Tigris also supports eager caching while listing the objects. This can be achieved by setting a header x-tigris-prefetch during list API request. This indicates Tigris to initiate automatic caching of listed objects in proximity to the list request's region. Subsequent Get requests for these objects will then take advantage of the cache.

Prefetch Request Syntax

GET /?list-type=2&continuation-token=ContinuationToken&delimiter=Delimiter&encoding-type=EncodingType&fetch-owner=FetchOwner&max-keys=MaxKeys&prefix=Prefix&start-after=StartAfter HTTP/1.1
Host: bucket.fly.storage.tigris.dev
x-tigris-prefetch: true

The supported header is x-tigris-prefetch, applicable during both ListObjects/ListObjectsV2 API requests. The AWS SDKs can be used to use this feature as AWS SDKs supports passing custom headers.