Why Is My Sync Taking Longer Than Normal?

Occasionally, your Fivetran syncs may take longer than usual. Learn about the common reasons below and find out how to address potential issues quickly.

Common causes of slow syncs

1. Data volume increases

A higher volume of data may increase your sync time. To check whether data volume is impacting your sync time, do the following:

1. In Fivetran, go to your connection page.
2. Select the Status tab.
3. In the Sync History chart, hover over a longer sync.
4. Make a note of the sync's Extract Volume.
5. Compare it with the volume from a shorter sync.

2. Manual schema changes

Adding new tables or columns to your connection schema can increase sync time. You can use the Fivetran Platform Connector to review recent schema modifications. For more information, see our Track schema changes documentation.

3. Automatic schema changes

If your connection's schema change settings are set to Allow all, we will automatically sync new columns and tables. New, large tables may lead to longer sync times.

To review your connection's new tables and columns, do the following:

1. In Fivetran, select Account Settings and then click Billing & Usage.
2. Select the Usage tab.
3. Go to the Usage breakdown section and click the MAR type dropdown.
4. Select the Initial Sync (Free) checkbox.

4. Significant source data changes

Mass updates or deletes in your source data may increase the number of changes we need to sync and, thus, the sync time.

You can use the Fivetran Platform Connector to check for significant changes that may impact your sync time. Fivetran generates records_modified log events that include a count field, representing the number of operations modified. You can also check the number of records that changed in your destination by querying the updated_at column with a WHERE clause.

NOTE: Child tables may not include an updated_at column if the records update automatically in conjunction with their parent record.

5. Network latency

Temporary network issues may impact your sync speed, especially when we connect to your source or destination database. Check with your network team to identify known latency or connectivity issues.

6. Source API rate limits (application connectors)

If you have reached your source's API rate limit, we may delay your sync until we can query the API again.

You can use the Fivetran Platform Connector to check delays related to API rate limits. Fivetran generates warning log events that provide information about the warning and affected tables.

7. Re-import tables

If a table contains a column that we can't sync incrementally, we must re-import the table in full. The sync frequency for these tables depends on how fast we can ingest the data from the source.

To find out whether your schema contains re-import tables, see the connector's documentation.

8. Nested API calls (application connectors)

We rely on nested API calls to sync data for some tables, which may impact the sync speed. If this applies, we display the following warning when you include these tables in your connection schema:

Not recommended: Syncing <table> table might slow down your sync.