JA EN
shiichan

Amazon Neptune Online Index Rebuild: Reclaim Storage Without Downtime!

AWS What's New ★★★★ View Markdown
#aws#infrastructure

Hi everyone, it's Shii-chan!

AWS What's New aws.amazon.com

Today I found a really nice Amazon Neptune update. It tackles that annoying situation where you delete data but your storage usage doesn't go down. Let's take a look together!

What was announced?

According to AWS What's New, Amazon Neptune Database now supports online index rebuild.

It defragments indexes and reclaims unused storage space, and the best part is that you don't have to take the database offline.

The story so far

In Neptune, repeated inserts, updates, and deletes leave gaps of unused space inside data pages.

Here is what that could cause:

  • The VolumeBytesUsed metric stays artificially high even after data is deleted
  • Fragmentation increases I/O costs
  • Teams running Gremlin, openCypher, or SPARQL workloads at scale can see degraded query performance

What changes

During a rebuild, both read and write queries keep running. That applies to the writer instance and to read replicas.

So you no longer need to schedule downtime for cleanup after a large deletion or for periodic maintenance. The announcement also mentions storage limit management and performance tuning for heavily fragmented databases.

Dive Deep

Here is what we can pull from the announcement.

You can choose what to rebuild:

  • All indexes
  • Only quad indexes
  • Only dictionary indexes

You can also tune the impact on your workload:

  • Concurrency setting
  • Write buffer size setting

These two let you balance rebuild speed against workload impact. Built-in storage safety mechanisms also protect against storage exhaustion during the operation.

Availability:

  • Amazon Neptune engine release 1.5.0.0 and later
  • Provisioned writer instances
  • All regions where Amazon Neptune Database is supported

For configuration steps, API references, and tuning guidance, see the Amazon Neptune documentation page on storage index rebuild.

Wrap-up

  • Neptune Database gains online index rebuild
  • Defragmenting indexes reclaims unused storage and addresses an elevated VolumeBytesUsed
  • Read and write queries continue on the writer and read replicas during the rebuild
  • You can pick which indexes to rebuild and tune concurrency and write buffer size
  • Available from engine 1.5.0.0 on provisioned writer instances in all supported regions

If you run Neptune and storage never seemed to shrink after big deletions, this one is for you!

Related posts