Flow Logs Sampling Configuration
We released a new configuration knob that allows customers to change the sampling rate for AWS and Azure on their own without contacting Kentik team.
That will allow customers to consume flow logs at the preferred rate fitting into the licensing strategy, assigning priority for certain types of traffic and being flexible by changing the sampling rate at any time and separately for each flow log exporter.
Licensing will be enforced after the sampling, so customers can use heavier sampling in some cases, and saving the licensed FPS for the another S3 buckets containing flow logs.
There is a slight difference in available options for AWS and Azure.
AWS flow log sampling
Historically Kentik was supporting a “legacy” mode of sampling where for the large files with flow logs we were randomly picking 10,000 flow records per file in S3 bucket and ingesting only those records into Kentik Data Engine. Since the number of the flow in a file can vary this was considered an “adaptive sampling” where larger files were getting more heavily sampled comparing to the smaller files. Another option was no sampling i.e. all the records were consumed from the file.
Moving forward we now support 3 options for AWS:
- Legacy sampling - random 10,000 flow records per file.
- Sampling rate - where user can provide the sampling rate in 1:N format (meaning 1 out N records to be picked up for an ingest into Kentik Data Engine), where N should be between 2 and 2000.
- Unsampled - all the records in a flow log file will be taken into ingest. Effectively that is the same as sampling rate 1:1.
Sampling rate can be configured when new flow log file is added, or changed for the existing exporter.
Azure flow log sampling
Flow log exporters for Azure before this release were supporting only Unsampled mode, where all the flows from the flow log file were processed by the Kentik Data Engine.
Since for some situations full flow log visibility might be not required, we added sampling knob that allows users to configure sampling rate 1:N format (meaning 1 out N records to be picked up for an ingest into Kentik Data Engine), where N should be between 2 and 2000.