0.3.0
Released 2016-08-05
Major Changes
Significantly improved performance, involving changes in the falco and sysdig repositories:
- Reordering a rule condition's operators to put likely-to-fail operators at the beginning and expensive operators at the end. [#95] [#104]
- Adding the ability to perform x in (a, b, c, ...) as a single set membership test instead of individual comparisons between x=a, x=b, etc. [#624] [#98]
- Avoid unnecessary string manipulations. [#625]
- Using
startswith
as a string comparison operator when possible. [#623] - Use
is_open_read
/is_open_write
when possible instead of searching through open flags. [#610] - Group rules by event type, which allows for an initial filter using event type before going through each rule's condition. [#627] [#101]
All of these changes result in dramatically reduced CPU usage. Here are some comparisons between 0.2.0 and 0.3.0 for the following workloads:
- Phoronix's
pts/apache
andpts/dbench
tests. - Sysdig Cloud Kubernetes Demo: Starts a kubernetes environment using docker with apache and wordpress instances + synthetic workloads.
- Juttle-engine examples : Several elasticsearch, node.js, logstash, mysql, postgres, influxdb instances run under docker-compose.
Workload | 0.2.0 CPU Usage | 0.3.0 CPU Usage |
---|---|---|
pts/apache | 24% | 7% |
pts/dbench | 70% | 5% |
Kubernetes-Demo (Running) | 6% | 2% |
Kubernetes-Demo (During Teardown) | 15% | 3% |
Juttle-examples | 3% | 1% |
As a part of these changes, falco now prefers rule conditions that have at least one evt.type=
operator, at the beginning of the condition, before any negative operators (i.e. not
or !=
). If a condition does not have any evt.type=
operator, falco will log a warning like:
Rule no_evttype: warning (no-evttype):
proc.name=foo
did not contain any evt.type restriction, meaning it will run for all event types.
This has a significant performance penalty. Consider adding an evt.type restriction if possible.
If a rule has a evt.type
operator in the later portion of the condition, falco will log a warning like:
Rule evttype_not_equals: warning (trailing-evttype):
evt.type!=execve
does not have all evt.type restrictions at the beginning of the condition,
or uses a negative match (i.e. "not"/"!=") for some evt.type restriction.
This has a performance penalty, as the rule can not be limited to specific event types.
Consider moving all evt.type restrictions to the beginning of the rule and/or
replacing negative matches with positive matches if possible.
Minor Changes
- Several sets of rule cleanups to reduce false positives. [#95]
- Add example of how falco can detect abuse of a badly designed REST API. [#97]
- Add a new output type "program" that writes a formatted event to a configurable program. Each notification results in one invocation of the program. A common use of this output type would be to send an email for every falco notification. [#105] [[#99](https://github.co
m//issues/99)] - Add the ability to run falco on all events, including events that are flagged with
EF_DROP_FALCO
. (These events are high-volume, low-value events that are ignored by default to improve performance). [#107] [#102]
Bug Fixes
- Add third-party jq library now that sysdig requires it. [#96]