Getting AWS CloudFront logs into Honeycomb

Honeycomb provides honeycloudfront to support ingestion of AWS CloudFront access logs These logs are useful for visualizing questions such as “How many cache misses are happening in CloudFront?” or “How much bandwidth is CloudFront saving us?”.

The source is available on Github and instructions for getting started are provided here.

This implementation supports Web Distributions. RTMP distributions are not supported. If you require RTMP support, please file an issue and CC the maintainers.

Prerequisites

honeycloudfront assumes access to an AWS access key ID and AWS secret access key with the proper permissions. It will attempt to obtain these via the default profile in ~/.aws/config, by the proper environment variables, or by an IAM EC2 instance profile. See the AWS guide on providing credentials for more details.

See the provided IAM policy JSON in the honeyaws repository for one example of a policy which has the proper permissions. This can be scoped down to more specific resources if desired.

Installation

honeycloudfront is available as part of the Honeycomb AWS Bundle or as a standalone binary.

To install honeycloudfront, use the following instructions:

deb

wget -q https://honeycomb.io/download/honeyaws/honeyaws_1.301_amd64.deb && \
      echo '2be1fc468e1a13f75c8a875d5be7d17b667fdc0139fb4319aa9c9f58549c2e88  honeyaws_1.301_amd64.deb' | sha256sum -c && \
      sudo dpkg -i honeyaws_1.301_amd64.deb

wget -q https://honeycomb.io/download/honeyaws/honeyaws-1.301-1.x86_64.rpm && \
      echo '986197990689ac961ccc178571c754b8a30d1f5ed0d320547628ab09cf6cd72a  honeyaws-1.301-1.x86_64.rpm' | sha256sum -c && \
      sudo rpm -i honeyaws-1.301-1.x86_64.rpm

wget -q -O honeycloudfront https://honeycomb.io/download/honeyaws/honeycloudfront/1.301 && \
      echo '5f6de0941a709102a9f588012ab8e530cf5c284d548fa0fb1affee23ace7625a  honeycloudfront' | sha256sum -c && \
      chmod 755 ./honeycloudfront

Usage

Use honeycloudfront interactively (for beginning exploration, debugging credential management, etc) or as a daemon. Try running some commands interactively at first to get a feel for using the tool and then configure it to run as a proper system service when you’re ready to be ingesting continuously.

Interactive

To show all distributions, invoke honeycloudfront ls:

$ honeycloudfront ls
EVDBLY2TVIYCVB
D11111ABCDEF8Q
S11A16G5KZMEQD

To ingest access logs from a distribution, use honeycloudfront ingest with one or more distribution names. Set your Honeycomb write key with the --writekey flag. By default the events will be sent to a dataset called aws-cloudfront-access.

Note: If access logs are not configured for the distribution it will throw an error. Please see the documentation on CloudFront access logs to learn how to enable this feature.

e.g. Ingesting logs from one distribution with ID S11A16G5KZMEQD:

$ honeycloudfront --writekey=YOUR_API_KEY ingest S11A16G5KZMEQD
...

You are currently logged in to the team, so we have populated the write key here to the first write key for that team.

Ingesting logs from multiple specific distributions:

$ honeycloudfront --writekey=YOUR_API_KEY ingest EVDBLY2TVIYCVB D11111ABCDEF8Q S11A16G5KZMEQD
...

honeycloudfront ingest without any arguments will use all available (“described”) distributions in your configured AWS region. With arguments, it will ingest logs for the specified load balancer names.

$ honeycloudfront --writekey=YOUR_API_KEY ingest
...ingesting logs from all distributions...

By default, the agent will drop state files (to avoid sending duplicate events) in the current working directory where it is invoked. To change where these files are kept, use the --statedir flag.

Sampling

Sampling is a great way to send fewer events (thereby keeping more history and reducing costs) while still preserving most relevant information. To set a sample rate while using one of the Honeycomb AWS tools, use the --samplerate flag. While the tools run, this base rate will be automatically adjusted by the Honeycomb AWS tools using dynamic sampling to keep more interesting traffic at a higher rate.

For instance, setting the sample flag to 20 will send 1 out of every 20 requests processed to Honeycomb by default. Fields such as elb_status_code are used to lower this ratio for rarer, but relevant, events such as HTTP 500-level errors.

$ honeyelb --samplerate 20 ...  ingest ...

Daemon

honeycloudfront, while supporting a interactive workflow for initial discovery and experimentation, is meant to be invoked as a long-running process by a system service manager.

To do this, edit the system init files (Upstart and systemd are supported) installed by the package manager to add the API key.

Exploration in Honeycomb

Once you receive data from honeycloudfront you will want to explore it. The descriptions of the sent fields is available in the AWS documentation for Web Distribution access logs.

Here are some suggestions for things to try:

GROUP BY x_edge_result_type and COUNT to see which and how many requests were served with cache status Hit, Miss, LimitExceeded, etc.
GROUP BY cs_uri_stem and MAX(time_taken) to see which URIs took the longest to serve
GROUP BY cs_uri_stem and MAX(sc_bytes) to see when the largest requests were served and how big they were in bytes