cloud-resources.md

Cloud Resources

This document attempts to catalog the cloud resources created by or required by scripts in this repository. At the time of writing, 16 August 2017, this document was not nearly comprehensive; please do not take it as such.

Test Fixtures

Our acceptance tests push quite a bit of data around. For a rough sense of scale, the biggest allocator tests create clusters with hundreds of gigabytes of data, and the biggest backup/restore tests push around several terabytes of data. This is far too much data to store in a VM image and far too much data to generate on demand, so we stash "test fixtures" in cloud blob storage.

At the moment, all our test fixtures live in Azure Blob Storage, Azure's equivalent of Amazon S3. The object hierarchy looks like this:

• roachfixtures{region}/
  • backups/ — the output of BACKUP... TO 'azure://roachfixtures/backups/FOO', used to test RESTORE without manually running a backup.
    • 2tb/
    • tpch{1,5,10,100}/
  • store-dumps/ — gzipped tarballs of raw stores (i.e., cockroach-data directories), used to test allocator rebalancing and backups without manually inserting gigabytes of data.
    • 1node-17gb-841ranges/ - source: RESTORE of tpch10
    • 1node-113gb-9595ranges/ - source: tpch100 IMPORT
    • 3nodes-17gb-841ranges/ - source: RESTORE of tpch10
    • 6nodes-67gb-9588ranges/ - source: RESTORE of tpch100
    • 10nodes-2tb-50000ranges/
  • csvs/ — huge CSVs used to test distributed CSV import (IMPORT...).

PLEA(benesch): Please keep the above list up to date if you add additional objects to the storage account. It's very difficult to track down an object's origin story.

Note that egress bandwidth is expensive. Every gigabyte of outbound traffic costs 8¢, so one 2TB restore costs approximately $160. Data transfer within a region, like from an storage account in the eastus region to a VM in the eastus region, is not considered outbound traffic, however, and so is free.

Ideally, we'd limit ourselves to one region and frolic in free bandwidth forever. In practice, of course, things are never simple. The eastus region doesn't support newer VMs, and we want to test backup/restore on both old and new VMs. So we duplicate the roachfixtures storage accounts in each region we spin up acceptance tests. At the moment, we have the following storage accounts:

• roachfixtureseastus — missing new VMs
• roachfixtureswestus — has new VMs

Syncing roachfixtures{region} Buckets

By far the fastest way to interact with Azure Blob Storage is the azcopy command. It's a bit of a pain to install, but the Azure CLIs (az and azure) don't attempt to parallelize operations and won't come close to saturating your network bandwidth.

Here's a sample invocation to sync data from eastus to westus:

for container in $(az storage container list --account-name roachfixtureseastus -o tsv --query '[*].name')
do
  azcopy --recursive --exclude-older --sync-copy \
    --source "https://roachfixtureseastus.blob.core.windows.net/$container" \
    --destination "https://roachfixtureswestus.blob.core.windows.net/$container" \
  --source-key "$source_key" --dest-key "$dest_key"
done

Since egress is expensive and ingress is free, be sure to run this on an azworker located in the source region—eastus in this case.

You can fetch the source and destination access keysfrom the Azure Portal or with the following Azure CLI 2.0 command:

az storage account keys list -g fixtures -n roachfixtures{region} -o tsv --query '[0].value'

TODO(benesch): install azcopy on azworkers.

TODO(benesch): set up a TeamCity build to sync fixtures buckets automatically.

Ephemeral Storage

Backup acceptance tests need a cloud storage account to use as the backup destination. These backups don't need to last beyond the end of each acceptance test, and so the files are periodically cleaned up to avoid paying for unnecessary storage.

TODO(benesch): automate cleaning out ephemeral data. Right now, the process is entirely manual.

To avoid accidentally deleting fixture data—which can take several days to regenerate—the ephemeral data is stored in separate storage accounts from the backup data. Currently, we maintain the following storage accounts:

• roachephemeraleastus
• roachephemeralwestus

Some acceptance tests follow a backup to ephemeral storage with a restore from that same ephemeral storage, triggering both ingress and egress bandwidth. To avoid paying for this egress bandwidth, we colocate storage accounts with the VMs running the acceptance tests, as we do for test fixtures.