Ongoing "background" writes to IndexedDB (logs for example) Use different bucket

Explanation

This page tests the latency for reading values from IndexedDB under various conditions. To begin the test, press "Start reading library" and note the number of "books" read per second --- this value updates continuously as long as the test runs.

You can also try the test when IDB is busy with other work by toggling the first checkbox to on. You should notice this interferes with the speed of the first task.

Lastly, try directing the background IDB task to a different Storage Bucket. When backing stores are sharded, this should reduce the degree of interference between the tasks. This feature can be enabled via about flags (link must be manually copied) or by passing the command line flag

--enable-features="IndexedDBShardBackingStores"

As of 16-Apr-2024 this flag is not enabled by default on any version of Chrome.

This test works best when

• Each test run is executed in a fresh Chrome (Chromium) profile
• The test is not run within a few seconds of browser startup (due to interference with startup tasks)
• The browser and system is doing as few other things as possible
• This includes displaying DevTools, as constant observation of internal state requires substantial resources

Reference results

Browser	Background task	Result (books/sec)
Linux desktop, 125.0.6382.3 (Official Build) dev (64-bit)	none	645
ditto	same bucket	575
ditto	different bucket	645