Estimate Serverless Usage with MovR

This tutorial shows you how to initialize and run the MovR workload on a CockroachDB Serverless cluster, then use the Request Unit consumption data to estimate a sufficient budget for the MovR workload.

Overview

MovR is a fictional company that offers users a platform for sharing vehicles, like scooters, bicycles, and skateboards, in select cities across the United States and Europe. The MovR team wants to use CockroachDB Serverless to run their high-growth, variable workload. They decide to test out a sample workload to see how it will perform and how much it will cost to run.

Before you begin

• Make sure you have already installed CockroachDB.
• Create a CockroachDB Serverless cluster.

Step 1. Get the cluster connection string

1. On the cluster's Overview page, click Connect.
2. Select General connection string from the Select option dropdown.
3. Open the General connection string section, then copy the connection string provided and save it in a secure location.

Step 2. Create the movr database

1. Connect to the SQL shell using the connection string you copied in Step 1:

   cockroach sql --url \
   'postgresql://<username>:<password>@serverless-host>:26257/defaultdb?sslmode=verify-full&options=--cluster%3D<routing-id>'
   

   Where:

   • <username> is the SQL user. By default, this is your CockroachDB Cloud account username.
   • <password> is the password for the SQL user. The password will be shown only once in the Connect to cluster dialog after creating the cluster.
   • <serverless-host> is the hostname of the CockroachDB Serverless cluster.
   • <routing-id> identifies your tenant cluster on a multi-tenant host. For example, funny-skunk-123.

2. In the SQL shell, create the movr database:

   CREATE DATABASE movr;
   

3. Return to the Connect to cluster dialog from Step 1 and select movr from the Database dropdown. You may have to refresh the page for movr to appear in the dropdown.

4. Copy the new General connection string.

Step 3. Load the movr workload

Exit the SQL shell and load the movr dataset using the new connection string:

  cockroach workload init movr \
  'postgresql://<username>:<password>@serverless-host>:26257/movr?sslmode=verify-full&options=--cluster%3D<routing-id>'

Step 4. Run the workload

Run the movr workload for 1 minute using the same SQL connection string as before:

  cockroach workload run movr \
  --duration=1m \
  'postgresql://<username>:<password>@serverless-host>:26257/movr?sslmode=verify-full&options=--cluster%3D<routing-id>'

You'll see per-operation statistics print to standard output every second:

  _elapsed___errors__ops/sec(inst)___ops/sec(cum)__p50(ms)__p95(ms)__p99(ms)_pMax(ms)
      1.0s        0           31.9           32.0      0.5      0.6      1.4      1.4 addUser
      1.0s        0            6.0            6.0      1.2      1.4      1.4      1.4 addVehicle
      1.0s        0           10.0           10.0      2.2      6.3      6.3      6.3 applyPromoCode
      1.0s        0            2.0            2.0      0.5      0.6      0.6      0.6 createPromoCode
      1.0s        0            9.0            9.0      0.9      1.6      1.6      1.6 endRide
      1.0s        0         1407.5         1407.8      0.3      0.5      0.7      4.1 readVehicles
      1.0s        0           27.0           27.0      2.1      3.1      4.7      4.7 startRide
      1.0s        0           86.8           86.9      4.7      8.4     11.5     15.2 updateActiveRides
      2.0s        0           26.0           29.0      0.5      1.1      1.4      1.4 addUser
      2.0s        0            8.0            7.0      1.2      2.8      2.8      2.8 addVehicle
      2.0s        0            2.0            6.0      2.6      2.8      2.8      2.8 applyPromoCode
      2.0s        0            0.0            1.0      0.0      0.0      0.0      0.0 createPromoCode
      2.0s        0            6.0            7.5      0.8      1.7      1.7      1.7 endRide
      2.0s        0         1450.4         1429.1      0.3      0.6      0.9      2.6 readVehicles
      2.0s        0           17.0           22.0      2.1      3.3      5.5      5.5 startRide
      2.0s        0           59.0           72.9      6.3     11.5     11.5     14.2 updateActiveRides
  ...

After the specified duration (1 minute in this case), the workload will stop and you'll see totals printed to standard output:

  _elapsed___errors_____ops(total)___ops/sec(cum)__avg(ms)__p50(ms)__p95(ms)__p99(ms)_pMax(ms)__result
     60.0s        0          85297         1421.6      0.7      0.3      2.6      7.1     30.4

Step 5. View your usage costs

1. In the CockroachDB Cloud Console, close the Connect to cluster dialog to return to your cluster's Overview page.

2. In the Usage this month section, click Estimate usage cost.

   The Estimate cost based on usage dialog appears.

3. Select Past 30 minutes as the time frame.

   Your Monthly estimate for this workload is displayed.

The Spend over time graph will be populated with the RU and storage you used running the movr workload, as well as any other usage you had over the last 30 minutes. The Monthly estimate for this workload is calculated based on this usage. Ideally your spend limit should be higher than this estimate to allow for any variability in the workload over the month. A cluster's spend limit is meant to prevent you from accidentally spending more than you are comfortable with, not to be the most accurate prediction of your costs.

Next steps

The MovR team can monitor their usage in the CockroachDB Cloud Console, and they will receive email alerts when the cluster approaches 50%, 75%, and 100% of its spend limit. If their workload grows and they reach the limits of the CockroachDB Serverless free offering, they can then set a spend limit.

To estimate the actual costs for your cluster, you should run your real workload and gather usage data. You can always edit your spend limit if your initial estimate turns out to be inaccurate or your budget changes.

See also

• Serverless Performance Benchmarking
• Manage a CockroachDB Serverless Cluster
• The MovR Example Application
• Example Apps

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