SSM rules

Elena Kostyuchenko

The rules in SSM consist of four parts:

<objects>: <trigger> | <conditions> | <commands>

The tables below describe possible values for objects, triggers, and conditions. The commands are described in the actions reference.

For more information on rules syntax, see the Define rules in SSM article; and more complex rules usage examples can be found in SSM rule usage examples.

File object properties
Property Abbreviation Description

accessCount(interval)

ac

Access count during the given time interval

accessCountTop(interval,N)

acTop

The topmost N for access count during the given time interval

accessCountBottom(interval,N)

acBot

The bottommost N for access count during the given time interval

accessCountTopOnStoragePolicy(interval, N, "$StoragePolicy")

acTopSp

The topmost N for access count with regard to a storage policy. The supported HDFS storage policies are:

  • COLD

  • WARM

  • HOT

  • ONE_SSD

  • ALL_SSD

  • LAZY_PERSIST

accessCountBottomOnStoragePolicy(interval,N, "$StoragePolicy")

acBotSp

The bottommost N for access count with regard to a storage policy during the last time interval

age

 — 

Time span from last modification moment to now

atime

 — 

Last access time

blocksize

 — 

Block size of the file

ecPolicy

 — 

Erasure coding policy of the file

inCache

 — 

File is in the cache storage

isDir

 — 

File is a directory

length

 — 

Length of the file in bytes. Currently, only numeric values are supported, which indicates the number of bytes

mtime

 — 

Last modification time of the file

path

 — 

File path in HDFS

storagePolicy

 — 

Storage policy of the file

unsynced

 — 

File is not synced

A condition can include one of two possible time values:

  • <time> — the exact time in the "yyyy-MM-dd HH:mm:ss:ms" format, now, or now+<TimeInterval>. For example, "2017-07-29 23:00:00", now+7day.

  • <TimeInterval> — a time interval described as a number and a unit (5sec, 5min, 5day) or in the format Time - Time, for example, now - "2016-03-19 23:00:00".

Conditions
Value Description Example

at <time>

Execute the rule at the given time

at "2017-07-29 23:00:00" at now

every <TimeInterval>

Execute the rule at the given frequency

every 1min

from <Time> [To <Time>]

Along with every expression to specify the time scope

every 1day from now every 1min from now to now+7day
Conditional operators
Operator Description Example

Logical operator

and, or, not

accessCount(1min) > 0 and length = 5KB

Digital operator

+, -, *, /, %

acTop - acBot > 0

Compare

>, >=, <, <=, ==, !=

accessCount(1min) > 0
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