Schedule trigger
editSchedule trigger
editSchedule triggers define when the watch execution should start based on date and time. All times are specified in UTC time.
Watcher uses the system clock to determine the current time. To ensure schedules are triggered when expected, you should synchronize the clocks of all nodes in the cluster using a time service such as NTP.
Keep in mind that the throttle period can affect when a watch is actually executed. The default throttle period is five seconds (5000 ms). If you configure a schedule that’s more frequent than the throttle period, the throttle period overrides the schedule. For example, if you set the throttle period to one minute (60000 ms) and set the schedule to every 10 seconds, the watch is executed no more than once per minute. For more information about throttling, see Acknowledgement and throttling.
Watcher provides several types of schedule triggers:
Hourly schedule
editA schedule
that triggers at a particular minute every
hour of the day. To use the hourly
schedule, you specify the minute (or minutes)
when you want the scheduler to start the watch execution with the minute
attribute.
If you don’t specify the minute
attribute for an hourly
schedule, it
defaults to 0
and the schedule triggers on the hour every hour--12:00
,
13:00
, 14:00
, and so on.
Configuring a once an hour schedule
editTo configure a once an hour schedule, you specify a single time with the minute
attribute.
For example, the following hourly
schedule triggers at minute 30 every hour--
12:30
, 13:30
, 14:30
, …:
{ "trigger" : { "schedule" : { "hourly" : { "minute" : 30 } } } }
Configuring a multiple times hourly schedule
editTo configure an hourly
schedule that triggers at multiple times during the
hour, you specify an array of minutes. For example, the following schedule
triggers every 15 minutes every hour--12:00
, 12:15
, 12:30
, 12:45
,
1:00
, 1:15
, …:
{ "trigger" : { "schedule" : { "hourly" : { "minute" : [ 0, 15, 30, 45 ] } } } }
Daily schedule
editA schedule
that triggers at a particular time
every day. To use the daily
schedule, you specify the time of day (or times)
when you want the scheduler to start the watch execution with the at
attribute.
Times are specified in the form HH:mm
on a 24-hour clock. You can also use the
reserved values midnight
and noon
for 00:00
and 12:00
, and
specify times using objects.
If you don’t specify the at
attribute for a daily
schedule, it defaults
to firing once daily at midnight, 00:00
.
Configuring a daily schedule
editTo configure a once a day schedule, you specify a single time with the at
attribute. For example, the following daily
schedule triggers once every
day at 5:00 PM:
{ "trigger" : { "schedule" : { "daily" : { "at" : "17:00" } } } }
Configuring a multiple times daily schedule
editTo configure a daily
schedule that triggers at multiple times during the day,
you specify an array of times. For example, the following daily
schedule
triggers at 00:00
, 12:00
, and 17:00
every day.
{ "trigger" : { "schedule" : { "daily" : { "at" : [ "midnight", "noon", "17:00" ] } } } }
Specifying times using objects
editIn addition to using the HH:mm
string syntax to specify times, you can specify
a time as an object that has hour
and minute
attributes.
For example, the following daily
schedule triggers once every day at 5:00 PM:
{ "trigger" : { "schedule" : { "daily" : { "at" : { "hour" : 17, "minute" : 0 } } } } }
To specify multiple times using the object notation, you specify multiple hours
or minutes as an array. For example, following daily
schedule triggers at
00:00
, 00:30
, 12:00
, 12:30
, 17:00
and 17:30
every day:
{ "trigger" : { "schedule" : { "daily" : { "at" : { "hour" : [ 0, 12, 17 ], "minute" : [0, 30] } } } } }
Weekly schedule
editA schedule
that triggers at a specific day and time
every week. To use the weekly
schedule, you specify the day and time (or days
and times) when you want the scheduler to start the watch execution with the on
and at
attributes.
You can specify the day of the week by name, abbreviation, or number (with Sunday being the first day of the week):
-
sunday
,monday
,tuesday
,wednesday
,thursday
,friday
andsaturday
-
sun
,mon
,tue
,wed
,thu
,fri
andsat
-
1
,2
,3
,4
,5
,6
and7
Times are specified in the form HH:mm
on a 24-hour clock. You can also use the
reserved values midnight
and noon
for 00:00
and 12:00
.
Configuring a weekly schedule
editTo configure a once a week schedule, you specify the day with the on
attribute
and the time with the at
attribute. For example, the following weekly
schedule
triggers once a week on Friday at 5:00 PM:
{ "trigger" : { "schedule" : { "weekly" : { "on" : "friday", "at" : "17:00" } } } }
You can also specify the day and time with the day
and time
attributes,
they are interchangeable with on
and at
.
Configuring a multiple times weekly schedule
editTo configure a weekly
schedule that triggers multiple times a week, you can
specify an array of day and time values. For example, the following weekly
schedule triggers every Tuesday at 12:00 PM and every Friday at 5:00 PM:
{ "trigger" : { "schedule" : { "weekly" : [ { "on" : "tuesday", "at" : "noon" }, { "on" : "friday", "at" : "17:00" } ] } } }
Alternatively, you can specify days and times in an object that has on
and
minute
attributes that contain an array of values. For example, the following
weekly
schedule triggers every Tuesday and Friday at 12:00 PM and 17:00 PM:
{ "trigger" : { "schedule" : { "weekly" : { "on" : [ "tuesday", "friday" ], "at" : [ "noon", "17:00" ] } } } }
Monthly schedule
editA schedule
that triggers at a specific day and time
every month. To use the monthly
schedule, you specify the day of the month and
time (or days and times) when you want the scheduler to start the watch execution
with the on
and at
attributes.
You specify the day of month as a numeric value between 1
and 31
(inclusive).
Times are specified in the form HH:mm
on a 24-hour clock. You can also use the
reserved values midnight
and noon
for 00:00
and 12:00
.
Configuring a monthly schedule
editTo configure a once a month schedule, you specify a single day and time with the
on
and at
attributes. For example, the following monthly
schedule triggers
on the 10th of each month at noon:
{ "trigger" : { "schedule" : { "monthly" : { "on" : 10, "at" : "noon" } } } }
You can also specify the day and time with the day
and time
attributes,
they are interchangeable with on
and at
.
Configuring a multiple times monthly schedule
editTo configure a monthly
schedule that triggers multiple times a month, you can
specify an array of day and time values. For example, the following monthly
schedule triggers at 12:00 PM on the 10th of each month and at 5:00 PM on the
20th of each month:
{ "trigger" : { "schedule" : { "monthly" : [ { "on" : 10, "at" : "noon" }, { "on" : 20, "at" : "17:00" } ] } } }
Alternatively, you can specify days and times in an object that has on
and at
attributes that contain an array of values. For example, the following monthly
schedule triggers at 12:00 AM and 12:00 PM on the 10th and 20th of each month.
{ "trigger" : { "schedule" : { "monthly" : { "on" : [ 10, 20 ], "at" : [ "midnight", "noon" ] } } } }
Yearly schedule
editA schedule
that triggers at a specific day and time
every year. To use the yearly
schedule, you specify the month, day, and time
(or months, days, and times) when you want the scheduler to start the watch
execution with the in
, on
, and at
attributes.
You can specify the month by name, abbreviation, or number:
-
january
,february
,march
,april
,may
,june
,july
,august
,september
,october
,november
anddecember
-
jan
,feb
,mar
,apr
,may
,jun
,jul
,aug
,sep
,oct
,nov
anddec
-
1
,2
,3
,4
,5
,6
,7
,8
,9
,10
,11
and12
You specify the day of month as a numeric value between 1
and 31
(inclusive).
The Times are specified in the form HH:mm
on a 24-hour clock. You can also use
the reserved values midnight
and noon
for 00:00
and 12:00
.
Configuring a yearly schedule
editTo configure a once a year schedule, you specify the month with the in
attribute,
the day with the on
attribute, and the time with the at
attribute. For
example, the following yearly
schedule triggers once a year at noon on January
10th:
{ "trigger" : { "schedule" : { "yearly" : { "in" : "january", "on" : 10, "at" : "noon" } } } }
You can also specify the month, day, and time with the month
, day
, and
time
attributes, they are interchangeable with in
, on
, and at
.
Configuring a multiple times yearly schedule
editTo configure a yearly
schedule that triggers multiple times a year, you can
specify an array of month, day, and time values. For example, the following
yearly
schedule triggers twice a year: at noon on January 10th, and at 5:00 PM
on July 20th.
{ "trigger" : { "schedule" : { "yearly" : [ { "in" : "january", "on" : 10, "at" : "noon" }, { "in" : "july", "on" : 20, "at" : "17:00" } ] } } }
Alternatively, you can specify the months, days, and times in an object that has
in
, on
, and minute
attributes that contain an array of values. For example,
the following yearly
schedule triggers at 12:00 AM and 12:00 PM on January 10th,
January 20th, December 10th, and December 20th.
{ "trigger" : { "schedule" : { "yearly" : { "in" : [ "jan", "dec" ], "on" : [ 10, 20 ], "at" : [ "midnight", "noon" ] } } } }
Cron schedule
editDefines a schedule
using a cron expression
that specifiues when to execute a watch.
While cron expressions are powerful, a regularly occurring schedule
is easier to configure with the other schedule types.
If you must use a cron schedule, make sure you verify it with
elasticsearch-croneval
.
Configure a cron schedule with one time
editTo configure a cron
schedule, you simply specify the cron expression as a
string value. For example, the following snippet configures a cron
schedule
that triggers every day at noon:
{ ... "trigger" : { "schedule" : { "cron" : "0 0 12 * * ?" } } ... }
Configure a cron schedule with multiple times
editTo configure a cron
schedule that triggers multiple times, you can
specify an array of cron expressions. For example, the following cron
schedule triggers every even minute during weekdays and every uneven
minute during the weekend:
{ ... "trigger" : { "schedule" : { "cron" : [ "0 0/2 * ? * MON-FRI"", "0 1-59/2 * ? * SAT-SUN" ] } } ... }
Use croneval to validate cron expressions
editElasticsearch provides a elasticsearch-croneval
command line tool
in the $ES_HOME/bin
directory that you can use to check that your cron expressions
are valid and produce the expected results.
To validate a cron expression, pass it in as a parameter to elasticsearch-croneval
:
bin/elasticsearch-croneval "0 0/1 * * * ?"
Interval schedule
editA schedule
that triggers at a fixed time interval. The
interval can be set in seconds, minutes, hours, days, or weeks:
-
"Xs"
- trigger everyX
seconds. For example,"30s"
means every 30 seconds. -
"Xm"
- trigger everyX
minutes. For example,"5m"
means every 5 minutes. -
"Xh"
- trigger everyX
hours. For example,"12h"
means every 12 hours. -
"Xd"
- trigger everyX
days. For example,"3d"
means every 3 days. -
"Xw"
- trigger everyX
weeks. For example,"2w"
means every 2 weeks.
If you don’t specify a time unit, it defaults to seconds.
The interval value differs from the standard time value used in Elasticsearch. You cannot configure intervals in milliseconds or nanoseconds.
Configuring an interval schedule
editTo configure an interval
schedule, you specify a string value that represents
the interval. If you omit the unit of time (s
,m
, h
, d
, or w
), it
defaults to seconds.
For example, the following interval
schedule triggers every five minutes:
{ "trigger" : { "schedule" : { "interval" : "5m" } } }