spellcheck/style leakybucket readme (#2294)
This commit is contained in:
parent
4c4b545e9b
commit
da6106bd23
|
@ -2,47 +2,49 @@
|
|||
|
||||
## Bucket concepts
|
||||
|
||||
Leakybucket is used for decision making. Under certain conditions
|
||||
enriched events are poured in these buckets. When these buckets are
|
||||
The Leakybucket is used for decision making. Under certain conditions,
|
||||
enriched events are poured into these buckets. When these buckets are
|
||||
full, we raise a new event. After this event is raised the bucket is
|
||||
destroyed. There are many types of buckets, and we welcome any new
|
||||
useful design of buckets.
|
||||
|
||||
Usually the bucket configuration generates the creation of many
|
||||
buckets. They are differenciated by a field called stackkey. When two
|
||||
events arrives with the same stackkey they go in the same matching
|
||||
Usually, the bucket configuration generates the creation of many
|
||||
buckets. They are differentiated by a field called stackkey. When two
|
||||
events arrive with the same stackkey they go in the same matching
|
||||
bucket.
|
||||
|
||||
The very purpose of these buckets is to detect clients that exceed a
|
||||
certain rate of attemps to do something (ssh connection, http
|
||||
authentication failure, etc...). Thus, the most use stackkey field is
|
||||
certain rate of attempts to do something (ssh connection, http
|
||||
authentication failure, etc...). Thus, the most used stackkey field is
|
||||
often the source_ip.
|
||||
|
||||
## Standard leaky buckets
|
||||
|
||||
Default buckets have two main configuration options:
|
||||
|
||||
* capacity: number of events the bucket can hold. When the capacity
|
||||
is reached and a new event is poured, a new event is raised. We
|
||||
call this type of event overflow. This is an int.
|
||||
|
||||
* leakspeed: duration needed for an event to leak. When an event
|
||||
leaks, it disappear from the bucket.
|
||||
leaks, it disappears from the bucket.
|
||||
|
||||
## Trigger
|
||||
|
||||
It's a special type of bucket with a zero capacity. Thus, when an
|
||||
event is poured in a trigger, it always raises an overflow.
|
||||
A Trigger is a special type of bucket with a capacity of zero. Thus, when an
|
||||
event is poured into a trigger, it always raises an overflow.
|
||||
|
||||
## Uniq
|
||||
|
||||
It's a bucket working as the standard leaky bucket except for one
|
||||
A Uniq is a bucket working like the standard leaky bucket except for one
|
||||
thing: a filter returns a property for each event and only one
|
||||
occurrence of this property is allowed in the bucket, thus the bucket
|
||||
is called uniq.
|
||||
|
||||
## Counter
|
||||
|
||||
It's a special type of bucket with an infinite capacity and an
|
||||
infinite leakspeed (it never overflows, neither leaks). Nevertheless,
|
||||
A Counter is a special type of bucket with an infinite capacity and an
|
||||
infinite leakspeed (it never overflows, nor leaks). Nevertheless,
|
||||
the event is raised after a fixed duration. The option is called
|
||||
duration.
|
||||
|
||||
|
@ -52,36 +54,41 @@ duration.
|
|||
|
||||
* type: mandatory field. Must be one of "leaky", "trigger", "uniq" or
|
||||
"counter"
|
||||
* name: mandatory field, but the value is totally open. Nevertheless
|
||||
|
||||
* name: mandatory field, but the value is totally open. Nevertheless,
|
||||
this value will tag the events raised by the bucket.
|
||||
* filter: mandatory field. It's a filter that is run when the decision
|
||||
to make an event match the bucket or not. The filter have to return
|
||||
|
||||
* filter: mandatory field. It's a filter that is run to decide whether
|
||||
an event matches the bucket or not. The filter has to return
|
||||
a boolean. As a filter implementation we use
|
||||
https://github.com/antonmedv/expr
|
||||
|
||||
* capacity: [mandatory for now, shouldn't be mandatory in the final
|
||||
version] it's the size of the bucket. When pouring in a bucket
|
||||
already with size events, it overflows.
|
||||
* leakspeed: leakspeed is a time duration (has to be parseable by
|
||||
https://golang.org/pkg/time/#ParseDuration). After each interval an
|
||||
|
||||
* leakspeed: leakspeed is a time duration (it has to be parsed by
|
||||
https://golang.org/pkg/time/#ParseDuration). After each interval, an
|
||||
event is leaked from the bucket.
|
||||
|
||||
* stackkey: mandatory field. This field is used to differentiate on
|
||||
which bucket ongoing events will be poured. When an unknown stackkey
|
||||
is seen in an event a new bucket is created.
|
||||
* on_overflow: optional field, that tells the what to do when the
|
||||
bucket is returning the overflow event. As of today, the possibility
|
||||
are these: "ban,1h", "Reprocess", "Delete".
|
||||
Reprocess is used to send the raised event back in the event pool to
|
||||
be matched agains buckets
|
||||
which instance of the bucket the matching events will be poured.
|
||||
When an unknown stackkey is seen in an event, a new bucket is created.
|
||||
|
||||
* on_overflow: optional field, that tells what to do when the
|
||||
bucket is returning the overflow event. As of today, the possibilities
|
||||
are "ban,1h", "Reprocess" or "Delete".
|
||||
Reprocess is used to send the raised event back to the event pool to
|
||||
be matched against buckets
|
||||
|
||||
### Fields for special buckets
|
||||
|
||||
#### Uniq
|
||||
|
||||
Uniq has an extra field uniq_filter which is too use the filter
|
||||
implementation from https://github.com/antonmedv/expr. The filter must
|
||||
return a string. All strins returned by this filter in the same
|
||||
buckets have to be different. Thus, if a string is seen twice it is
|
||||
dismissed.
|
||||
* uniq_filter: an expression that must comply with the syntax defined
|
||||
in https://github.com/antonmedv/expr and must return a string.
|
||||
All strings returned by this filter in the same buckets have to be different.
|
||||
Thus if a string is seen twice, the event is dismissed.
|
||||
|
||||
#### Trigger
|
||||
|
||||
|
@ -89,9 +96,9 @@ Capacity and leakspeed are not relevant for this kind of bucket.
|
|||
|
||||
#### Counter
|
||||
|
||||
It's a special kind of bucket that raise an event and is destroyed
|
||||
after a fixed duration. The configuration field used is duration and
|
||||
must be parseable by https://golang.org/pkg/time/#ParseDuration.
|
||||
* duration: the Counter will be destroyed after this interval
|
||||
has elapsed since its creation. The duration must be parsed
|
||||
by https://golang.org/pkg/time/#ParseDuration.
|
||||
Nevertheless, this kind of bucket is often used with an infinite
|
||||
leakspeed and an infinite capacity [capacity set to -1 for now].
|
||||
|
||||
|
@ -126,17 +133,17 @@ leakspeed and an infinite capacity [capacity set to -1 for now].
|
|||
|
||||
[This is not dry enough to have many details here, but:]
|
||||
|
||||
The bucket code is triggered by `InfiniBucketify` in main.go.
|
||||
There's one struct called buckets which is for now a
|
||||
The bucket code is triggered by `InfiniBucketify` in `main.go`.
|
||||
There is one struct called buckets which is for now a
|
||||
`map[string]interface{}` that holds all buckets. The key of this map
|
||||
is derivated from the filter configured for the bucket and its
|
||||
stackkey. This looks like complicated, but in fact it allows us to use
|
||||
only one structs. This is done in buckets.go.
|
||||
is derived from the filter configured for the bucket and its
|
||||
stackkey. This looks complicated, but it allows us to use
|
||||
only one struct. This is done in buckets.go.
|
||||
|
||||
On top of that the implementation define only the standard leaky
|
||||
bucket. A goroutine is launched for every buckets (bucket.go). This
|
||||
On top of that the implementation defines only the standard leaky
|
||||
bucket. A goroutine is launched for every bucket (`bucket.go`). This
|
||||
goroutine manages the life of the bucket.
|
||||
|
||||
For special buckets, hooks are defined at initialization time in
|
||||
manager.go. Hooks are called when relevant by the bucket gorourine
|
||||
when events are poured and/or when bucket overflows.
|
||||
manager.go. Hooks are called when relevant by the bucket goroutine
|
||||
when events are poured and/or when a bucket overflows.
|
||||
|
|
Loading…
Reference in a new issue