Report on compaction task instance IDs

[patchwork01]

Background

With compaction on EC2, multiple tasks can run on the same EC2 instance. We currently generate a UUID to identify each compaction task when it starts, and store that in the status store.

In the past we've noticed varying performance depending on how many tasks ran on the same EC2 instance, as in the following issue:

• Inconsistent scheduling & speed of compaction tasks on EC2 #3329

Description

We'd like to record any information about which underlying AWS resources the compaction task ran on, and include it in the compaction task report.

Analysis

For compaction on EC2 we should be able to include the EC2 instance ID, availability zone and container ID. We currently log the EC2 instance ID, availability zone and ARN, but we don't put it in the status store.

We can look at what we can include in Fargate.