Billing

Fauna billing is primarily based on the resources that you use in your queries. Fauna provides a generous free tier so that you can learn how the service works. You can also choose to purchase higher tiers that include predictable pricing or support. See the pricing page for more information.

This page describes how resource usage is counted.

Definitions

Document

A JSON object stored in a Fauna database, which includes user-provided documents and Fauna schema documents, such as those describing databases, collections, indexes, keys, user-defined functions, and roles.

Query

An expression of one or more FQL functions intended to achieve, or return, a result. Queries are executed as an all-or-nothing transaction by Fauna.

Resources

For billing purposes, use of the following resources is counted:

Read operations

  • One read operation is counted when up to 4 KiB of a document is read from storage. A 20 KiB document requires five read operations, a 4.1 KiB document requires two read operations.

    When a query involves a distinct document multiple times, the document is only read once, not once per instance in the query.

  • One read operation is counted when up to 4 KiB of tuples is fetched from an index.

    Also, one read operation per index partition is counted. An index with no terms defined has eight partitions, so seven more read operations are counted beyond the number required to read a page from the index.

    When a query involves a distinct page from an index multiple times, the index page is only read once, not once per use in the query.

  • One read operation is counted when up to 4 KiB of document history is read from storage. A 0.5 KiB document with more than 32 KiB of historical versions requires eight read operations.

  • Read operations for authentication or identity checks are counted according to the size of the token or key. One read operation is counted when up to 4 KiB is read.

  • Read operations are counted whether the query fails or not.

  • If a query has to be retried due to conflicts with other concurrent queries that are writing to the same documents, the query is retried and incurs read operations again.

  • Read operations are not counted for the parts of a query involved in write operations. For example, if you Create a document, the result is incidentally read after the write completes, but does not accrue read operations.

See the x-byte-read-ops response header in the Per query metrics section.

Write operations

  • One write operation is counted when up to 1 KiB of a document is written to storage. A 20 KiB document requires 20 write operations, a 1.1 KiB document requires two write operations.

  • Index writes, for documents that are created, updated, or deleted, do incur write operations: one write operation is counted when up to 1k of index data is written, even when those writes span multiple indexes.

    Writing an index entry involves modifying four locations in index storage, and includes the field values in the terms and values definitions plus the Reference and Timestamp from the covered document.

    You can reduce write operations during index creation by creating the documents to be indexed first, and the index afterwards. Indexes that were created after their source documents need to backfill their entries, which is a process that is handled by a background job (except when the number of documents is less than 128). For background job processing, Fauna only charges compute operations (read and write operations are not counted). You cannot query the index until the backfill is complete.

  • For queries that fail, write operations are not counted.

See the x-byte-write-ops response header in the Per query metrics section.

Compute operations

  • One compute operation is counted for up to fifty function calls.

  • During index writes, compute operations are incurred as if a Lambda function called Select once each for the terms and values definitions.

    When terms or values are not defined, the associated Select call does not occur, reducing the function call count.

    When neither terms nor values are defined, the Lambda is not called, so no compute ops are incurred.

  • User-defined functions might call many functions with each invocation. All function calls are counted. Compute operations might grow rapidly when using functions such as Map and Reduce, or when calling a UDF recursively.

  • The import command in fauna-shell performs compute operations.

See the x-compute-ops response header in the Per query metrics section.

Streaming operations

  • Each streamed event counts two read operations which includes an initial 4k bytes read from storage, plus one read operation per 4k bytes read from storage, per subscriber.

    For example, when a stream event involves a single 20K document, six read operations are counted.

  • One compute operation is counted for every one second that a stream is held open, per subscriber.

See the x-byte-read-ops and x-compute-ops response headers in the Per query metrics section.

Storage

  • Documents are stored on disk, and the amount of space occupied is charged monthly.

  • Indexes are also stored on disk, and contribute to the storage that is charged monthly. The size of indexes varies with the size of the data that is indexed.

Storage reporting is a continuous process, where the storage occupied in each database is determined about once per day. The billed amount for storage is determined by taking an average of the daily storage reports in a calendar month.

There can be some inaccuracy in storage reporting due to server topology changes. When this occurs, the reported storage is less than the actual, resulting in lower billing.

Be aware that Fauna stores all revisions to a document separately. Each document update contributes to the storage total. Deleting unused documents and their revisions reduces required storage. Setting the document ttl field, or the collection history_days or ttl_days fields, can indirectly reduce storage.

Removal is handled by a background task, so once a document (including collections, databases, indexes, keys, roles, and tokens) "expires" due to the setting in the ttl field, it could be some time (hours or days) before the removal occurs. There is no guarantee that removal occurs.

As of version 3.0.0, the ttl field is honored on read — an expired but not yet removed document behaves as if removal is complete. But, until removal is completed by background task processing, you can continue to access the history of the document, provided you have its reference, using the Events function.

Data transfer

Data transfer is included in the cost calculation for read, write, and compute operations. There is no separate billing for data transfer.

Snapshots

Snapshots for backups incur charges in three ways:

  1. Snapshot creation: the number of compute operations required to produce a snapshot. One hundred compute operations are charged per megabyte of data captured in the snapshot, with a base of 20,000 compute operations.

    For example, for a 1-gigabyte database, the total compute operations required are 100 compute operations/megabyte × 1,000 MiB
    20,000 compute operations = 120,000 compute operations.

    Pricing for compute operations varies by Region Group. If the cost for compute operations is $2.03/million, you are charged $0.24 USD for a 1-gigabyte snapshot in the US Region Group.

  2. Snapshot retention: the number of gigabytes required to store cumulative snapshots.

    For example, the storage occupied for 30 days of 10 MiB snapshots is 0.3 GiB, 30 days × 0.01 GiB.

    Pricing for storage varies by Region Group. If the cost of storage is $0.05 USD per gigabyte per day, you are charged $0.02 USD to store 30 days of snapshots at 10 MiB each in the EU Region Group.

    Snapshots exist at the account level and are retained even if the original database is deleted or backups for a database are turned off. This is convenient when you need to recover a database that you deleted accidentally.

  3. Snapshot restore/copy: the number of compute operations required to restore or copy a snapshot. One hundred compute operations are charged per megabyte of data restored/copied from a snapshot.

    For example, for a 1-gigabyte snapshot, the total compute operations to restore/copy the snapshot are 100 compute operations × 1,000 MiB = 100,000 compute operations.

    Pricing for compute operations varies by Region Group. If the cost for compute operations is $2.25/million, you are charged $0.23 USD to restore/copy a 1 GiB snapshot to the Classic Region Group.

See the pricing page for current snapshot rates.

Dashboard usage

Using the Fauna Dashboard to navigate your databases, collections, indexes, functions, keys, and tokens, plus running FQL or GraphQL queries, consumes read, write, and compute operations. The Dashboard uses the same kinds of query that you might use to fetch the information displayed by the Dashboard.

The Dashboard tries to display the latest information available, so every time you navigate to a new display, or refresh your browser, more queries are executed to populate the display.

Browsing your databases using the Dashboard incurs only a small fee. For you to incur $0.01 USD on your bill, you would need to consume more than 20,000 read operations, or more than 4,000 write operations. If your monthly usage is lower than your plan limits, Dashboard use does not cost extra.

Here are some "rules of thumb" for Dashboard usage:

Activity Expected read ops

Every time you visit the Home page

48

Every time you visit a database Overview page

32
+ <# of collections>
+ <# of indexes>

Every time you visit the Collection details page

8
+ <# of documents>

Every time you click the Collections button (in the left navigation pane)

8
+ <# of Collections>
plus the cost of loading the first Collection’s details.

Functions, indexes, keys, access providers, and roles are represented by documents so browsing the other pages incurs costs as well.

Varies

Per query metrics

Fauna FQL queries are performed over HTTP connections, and responses include headers that indicate the resources used in the current query.

For example, for the following FQL query performed with the JavaScript driver:

client.query(
  q.Map(
    q.Paginate(q.Match(q.Index('all_letters'))),
    q.Lambda("X", q.Get(q.Var("X")))
  )
)
.then((ret) => console.log(ret))

The following response headers were included with the query result:

{
  'alt-svc': 'clear',
  'content-length': '4459',
  'content-type': 'application/json;charset=utf-8',
  date: 'Tue, 17 Nov 2020 22:57:46 GMT',
  via: '1.1 google',
  'x-byte-read-ops': '34',
  'x-byte-write-ops': '0',
  'x-compute-ops': '2',
  'x-faunadb-build': '20.11.00.rc8-01f9c94',
  'x-query-bytes-in': '120',
  'x-query-bytes-out': '4459',
  'x-query-time': '7',
  'x-read-ops': '27',
  'x-storage-bytes-read': '3047',
  'x-storage-bytes-write': '0',
  'x-txn-retries': '0',
  'x-txn-time': '1605653866258457',
  'x-write-ops': '0'
}

The query reads from a collection with all 26 letters of the English alphabet, and it used the all_letters index to do so. The metrics associated with billing include:

  • x-byte-read-ops is 34, which is one read operation for each of 26 letters, and eight read operations for the index which has no terms defined. This value contributes to the read operations billing.

  • x-byte-write-ops is 0, as no writes were performed during the query. This value contributes to the write operations billing.

  • x-compute-ops is 2. The Map, Paginate, and Index functions are called once each, Lambda and its Get and Var functions are called 26 times each, for a total of 81 function calls. The compute operations is function calls / 50, rounded up. This value contributes to the compute operations billing.

Note that the x-read-ops, x-query-bytes-in, x-query-bytes-out, x-write-ops, x-storage-bytes-read, and x-storage-bytes-write headers refer to legacy query accounting, and are not used in billing calculations.

You can use this information to accurately calculate the resource cost of running your queries, especially if your applications execute them frequently.

The Web Shell provides this information as a tooltip for each query result. Hover your pointer over the i in the white circle to see the tooltip.

Billable operations in the Web Shell
The Fauna GraphQL API does not currently implement per-query billing headers.

Exceeding limits

If you are using the Free plan and exceed the stated limits (as listed on the pricing page) in a calendar month, the following actions take place:

  1. An email notification is sent to the email address associated with your account, advising you of the situation.

  2. If you continue to use the service without upgrading to a paid plan, the keys/tokens that you use to access the service (from client applications) are temporarily revoked.

    The Dashboard no longer lists databases that exist in your account. No data is lost or removed.

    The period between notification and revocation varies, but is about one week.

  3. If your access to databases is temporarily revoked, you can upgrade to a paid plan to have your keys/tokens reinstated. Reinstatement is a manual process, so your databases continue to look unavailable after upgrade.

Reinstating access for temporarily revoked keys/tokens requires contact with support@fauna.com, even if you have upgraded to a paid plan.

As mentioned, the Free plan limits are per calendar month. The metrics for account limits are reset on the first day of a calendar month. Accounts with revoked access have their access reinstated on the last day of a calendar month.

For paid plans, exceeding the plan limits does not cause your account to be paused. Usage of the database beyond the limits is billed at the on-demand metering rate.

Plan downgrades

Should you ever need to downgrade your current to a lower plan, or to the Free plan, you must contact support@fauna.com.

  • There are no self-service downgrades.

  • The downgrade to the new plan occurs on the first business day of the following month. Your current plan remains in effect until then.

  • There is no "stop all charges now" option.

  • During the downgrade, a final invoice for the current plan is generated that covers the usage in the current month, including on-demand metering incurred since the downgrade request.

  • Once the downgrade is complete, the new plan takes effect.

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