Azure SQL db with data sync costs increasing

Arthur Hanssens 1 Reputation point
2021-10-06T09:33:55.727+00:00

I set up a data sync on an azure sql db on 17 september. For a few days, the running costs of this were $1.22/day, but on 23 September this went up to $8/day, without me making any changes (the sync has also not been triggered since first sync).

I want to understand why this is happening and how I can avoid it? There seems to be no reliable way of estimating cost of running Azure SQl db with data sync.

Azure SQL Database
Azure Cost Management
Azure Cost Management
A Microsoft offering that enables tracking of cloud usage and expenditures for Azure and other cloud providers.
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  1. Alberto Morillo 32,886 Reputation points MVP
    2021-10-06T11:02:11.92+00:00

    The service it self is free but there are charges for data movement, resource usage and egress charges. If you need to sync with replicas that are located on premises or located on different Azure regions then costs of data transfer between data centers in different regions will apply. The same if data has to be transferred to on-premises replicas, egress charges will apply. On those scenarios, the initial sync may prove to be expensive as conflicts between the hub database and the replicas need to be resolved by SQL Data Sync and depending on the size of the databases it may take hours and maybe days.

    To better estimate charges for data movement in and out of your SQL Database please refer to this page.

    You can reduce your costs by minimizing the data traffic leaving a data center.

    • Locate your Data Sync server in the region where you have the most data traffic.
    • Locate your sync group hub in the data center to where you have the most data traffic.
    • Synchronize only as often as is required by your business needs.
    • This means some sync groups will synchronize often and others less frequently. For example, do you need your payroll sync group to synchronize every five minutes or would weekly or monthly be sufficient?

    Even if you don't use Azure SQL Data Sync databases (hub databases and member databases in Azure) you still have to pay per service tier selected and compute resources assigned to the database (CPU, storage, memory). You also have to pay for backup storage and long term retention (if long-term backup is used.