Migration job metrics

Database Migration Service collects and displays migration job metrics that represent the health and progress of your data migration process. This page describes the following areas associated with migration job metrics:

Metrics available on the migration job details page

The migration job details page shows several diagrams that can help you understand the current state and progress of your migration job. Some diagrams provide database-level information, while others focus on table-level data.

Example diagrams for migration job metrics Database Migration Service.
Figure 1. Sample observability diagrams in Database Migration Service. (click to enlarge)
Example diagrams for migration job metrics Database Migration Service.

Expand the following sections to learn more about each diagram and its associated metric.

Throughput

The Throughput diagram uses the migration_job/write_bytes_count metric to represent how much data (in bytes) Database Migration Service has written to your destination database. This metric is sampled every 60 seconds. You can use it to observe the write speed of your migration.

This metric is available in the aggregated view, as well as separately for each table included in your migration job.

Full dump volume

The Full dump volume diagram shows the progress of the full dump phase expressed as the percentage of total full dump data migrated. This metric is available in the aggregated view, as well as separately for each table included in your migration job.

  • The aggregated view diagram uses the migration_job/fulldump_progress_percentage metric.
  • The table-level diagrams use the migration_job/fulldump_progress_percentage_per_object metric.

Storage usage in total bytes

The Storage usage in total bytes diagram uses the Cloud SQL for PostgreSQL database/disk/bytes_used metric to show how much data (in bytes) is stored in the migrated database in your destination Cloud SQL for PostgreSQL instance. You can use this information to estimate the progress of your migration job.

Replication delay

The Replication delay diagram uses the migration_job/max_replica_sec_lag metric to represent the time difference between the moment when Database Migration Service starts reading Change Data Capture (CDC) information in your source, and the moment when that information is fully replicated in your destination. You can use this information to estimate when to promote the migration job (you want to begin the cutoff process when replication lag is the lowest).

View metrics on the migration job details page

To view metric diagrams on the migration job details page, perform the following steps:

  1. In the Google Cloud console, go to the Migration jobs page.

    Go to Migration jobs

  2. In the Jobs tab, click the display name of your migration job.

    The migration job details page opens.

  3. In the Monitoring section, use the View menu to adjust which diagrams you want to display:

    • To view metrics aggregated for the whole migration job, click View > Aggregated.
    • To view table-level metrics, click View > Tables, and then select your tables.

Metrics available in Cloud Monitoring

The following table describes all migration job metrics you can use to create charts in Metrics Explorer for heterogeneous Oracle migrations. The complete metrics Database Migration Service metrics reference lists several additional metrics, but they are not available for heterogeneous Oracle migrations.

You can also use the Cloud SQL for PostgreSQL database/disk/bytes_used metric and compare it with the total size of your source databases to estimate the migration job progress.

Metric type Launch stage
Display name
Kind, Type, Unit
Monitored resources		 Description
Labels
migration_job/fulldump_progress_percentage BETA  (project)
Fulldump progress percentage
GAUGE, DOUBLE, %
datamigration.googleapis.com/MigrationJob 		Progress percentage of the initial fulldump of the migration job.. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.
migration_job/fulldump_progress_percentage_per_object BETA  (project)
Fulldump progress percentage per object
GAUGE, DOUBLE, %
datamigration.googleapis.com/MigrationJob 		Progress percentage of the initial fulldump of a single table in a migration job. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.
migration_job/write_bytes_count BETA
Write Bytes Count
DELTA, INT64, By
datamigration.googleapis.com/MigrationJob 		Number of bytes written to the destination. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.
database: Database name.
migration_job/max_replica_bytes_lag BETA
Max lag bytes of the migration job data.
GAUGE, INT64, By
datamigration.googleapis.com/MigrationJob 		Current replication lag, aggregated across all of the migration job's data. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.
database: Database name.
migration_job/max_replica_sec_lag BETA
Max lag in seconds of the migration job data
GAUGE, INT64, s
datamigration.googleapis.com/MigrationJob 		Current replication lag, aggregated across all of the migration job's data. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.
database: Database name.
migration_job/unsupported_events_count BETA  (project)
Unsupported Events Count
DELTA, INT64, By
datamigration.googleapis.com/MigrationJob 		Number of unsupported events per migration and per table. Sampled every 60 seconds. After sampling, data is not visible for up to 180 seconds.