Log streaming: Amazon Kinesis Data Streams

Fastly's Real-Time Log Streaming feature can send log files to Amazon Kinesis Data Streams. Amazon Kinesis Data Streams (KDS) is a real-time data streaming service that can continuously capture data from a variety of sources.

How Amazon Kinesis Data Streams work with Fastly log streaming

Amazon KDS sends data records to a stream. Each stream comprises one or more shards. A shard represents a fixed amount of processing capacity and the total processing capacity of a stream is determined by the number of shards. The number of shards may be increased or decreased over the lifetime of a stream. This is important because the Fastly Kinesis logging endpoint monitors the number of shards and attempts to uniformly distribute the log data records across the available shards. When the number of shards for a stream changes, the Fastly Kinesis logging endpoint automatically adjusts in response. The goal is to make the best use of the throughput capability of the stream while minimizing the configuration overhead required for our customers.

If the log volume exceeds the throughput capacity of the stream, Amazon KDS will return errors to our system that indicate that the stream is being throttled and that may prevent some logs from being delivered. AWS CloudWatch provides a metric for Kinesis Data Streams, WriteProvisionedThroughputExceeded, that can be used to monitor this so that adjustments to the stream capacity can be made as necessary.

Prerequisites

Before adding Amazon KDS as a logging endpoint for Fastly services, we recommend creating Identity and Access Management (IAM) credentials in your AWS account specifically for Fastly. Our recommended way for doing this is by creating an AWS IAM role, which lets you grant temporary credentials. For more information, see Creating an AWS IAM Role for Fastly Logging. Alternatively, create an IAM user and grant the user kinesis:PutRecords and kinesis:ListShards permissions for the logging stream. For more information, see Amazon's guidance on understanding and getting your AWS credentials.

Adding Amazon Kinesis as a logging endpoint

After you've registered for an AWS account and created an IAM user in Amazon Kinesis, follow these instructions to add Amazon KDS as a logging endpoint:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

{
  "timestamp": "%{strftime(\{"%Y-%m-%dT%H:%M:%S%z"\}, time.start)}V",
  "client_ip": "%{req.http.Fastly-Client-IP}V",
  "geo_country": "%{client.geo.country_name}V",
  "geo_city": "%{client.geo.city}V",
  "host": "%{if(req.http.Fastly-Orig-Host, req.http.Fastly-Orig-Host, req.http.Host)}V",
  "url": "%{json.escape(req.url)}V",
  "request_method": "%{json.escape(req.method)}V",
  "request_protocol": "%{json.escape(req.proto)}V",
  "request_referer": "%{json.escape(req.http.referer)}V",
  "request_user_agent": "%{json.escape(req.http.User-Agent)}V",
  "response_state": "%{json.escape(fastly_info.state)}V",
  "response_status": %{resp.status}V,
  "response_reason": %{if(resp.response, "%22"+json.escape(resp.response)+"%22", "null")}V,
  "response_body_size": %{resp.body_bytes_written}V,
  "fastly_server": "%{json.escape(server.identity)}V",
  "fastly_is_edge": %{if(fastly.ff.visits_this_service == 0, "true", "false")}V
}