Billing on Confluent Cloud for Apache Flink

Confluent Cloud for Apache Flink®️ is a serverless stream-processing platform with usage-based pricing, where you are charged only for the duration that your queries are running.

You configure Flink by creating a Flink compute pool. You are charged for the size of the compute pool, which scales elastically based on the resources consumed by the Flink statements. You can configure the maximum size of a compute pool to limit your spending.

There is no additional charge for reading data in and out of Apache Kafka® from Flink. Standard Kafka networking rates apply, based on cluster type.

CFUs

A CFU is a logical unit of processing power that is used to measure the resources consumed by Confluent Cloud for Apache Flink. Each Flink statement consumes a minimum of 1 CFU-minute but may consume more depending on the needs of the workload.

CFU billing

You are billed for the total number of CFUs consumed inside a compute pool per minute. Usage is stated in hours in order to apply hourly pricing to minute-by-minute use. For example, 30 CFU-minutes is 0.5 CFU-hours.

CFU pricing
$0.21/CFU-hour, calculated by the minute ($0.0035/CFU-minute)

Cost Management

You can’t define the number of CFUs required for individual statements. CFUs are counted by Confluent Cloud for Apache Flink. You can configure the maximum size of a compute pool to limit your spending by setting a parameter named MAX_CFU, which sets an upper limit on the hourly spend on the compute pool. If the size of the workload in a pool exceeds MAX_CFU, new statements are rejected. Existing workloads continue running but may experience increased latency.

For more information on CFU prices, see Confluent Cloud Pricing.

Pricing examples

Data streaming is a real-time business, and data streams oscillate on a minute-by-minute basis, creating peaks and troughs of utilization. You don’t want to allocate and overpay for processing capacity that you aren’t using. With Confluent Cloud for Apache Flink, you pay only for the processing power that you actually use.

The following examples provide additional detail on how pricing works when processing streams using Confluent Cloud for Apache Flink.

Data exploration and discovery

Most SQL queries are short-running, interactive queries that help software and data engineers understand the streams they have access to. Querying the streams directly is an important and necessary step in the iterative development of apps and pipelines.

In the following example, one user executes five different queries. Unlike other Flink offerings, Confluent Cloud for Apache Flink’s serverless architecture charges you only for the five minutes when these queries are executing, with all users able to share the resources of a single compute pool. It doesn’t matter if these queries are executed by the same person, by five different people at the same time or, as shown below, at different points in the hour.

Diagram showing five SQL queries and corresponding CFUs in Confluent Cloud for Apache Flink®️.
Example pricing calculation
  • Number of queries executed = 5
  • Total CFU-minutes consumed = 5
  • Total charge: 5 CFU-minutes x $0.0035/CFU-minute = $0.0175

Note: The charge appears on the invoice as “0.083 CFU-hours x $0.21/CFU-hour”.

Many data streaming apps and statements

Data streaming architectures are composed of many applications, each with their own workload requirements. An architecture can be a mix of interactive, terminating statements and continuous, streaming statements. Confluent Cloud for Apache Flink automatically scales the processing power of the Flink compute pool up and down in real-time to ensure your apps have the processing power they need, while charging only for the minutes needed.

In the following example, five streaming statements are running in a single compute pool. The data streams are oscillating, and you can see spikes of utilization for short periods within the hour. Each statement attracts a minimum price of 1 CFU-minute ($0.0035 in this example) and is automatically scaled up and down as needed on a per-minute basis.

Diagram showing five SQL queries with changing workloads and corresponding CFUs in Confluent Cloud for Apache Flink®️.
Statement CFU-minutes Statement Type
Q1 5 Interactive
Q2 60 Streaming
Q3 110 Streaming
Q4 10 Interactive
Q5 124 Streaming
Total 309  
Example pricing calculation
  • Number of statements executing = 5
  • Total CFU-minutes consumed = 309
  • Total charge: 309 CFU-minutes x $0.0035/CFU-minute = $1.0815

Note: The charge appears on the invoice as “5.15 CFU-hours x $0.21/CFU-hour”.