read
Reads events or metrics from various remote backends via adapters supported by Juttle and emits them into the flowgraph. The read source honors standard parameters as well as adapter-specific options.
read <adapter> [-from moment] [-to moment] [-last duration]
[adapter-options] [filter-expression]
| ...
| Parameter | Description | Required? |
|---|---|---|
adapter |
Name of the adapter to connect to the backend. | Yes |
-from |
Start time, inclusive: stream points whose time stamps are greater than or equal to the specified moment. See Time notation in Juttle for syntax information. |
Depending on the adapter |
-to |
End time, exclusive: stream points whose time stamps are less than the specified moment, which is less than or equal to :now: See Time notation in Juttle for syntax information. :information_source: Note:To stream live data only, omit -from and use -to :end: To combine historical and live data, specify a -from value in the past and use -to :end: |
Depending on the adapter |
-last |
Shorthand syntax for to -from (:now: - duration) -to :now: this specifies a historical time window of the specified duration that ends at the present moment. |
No |
adapter-options |
Additional -<key> <value>options specific to reading from the chosen backend, handled by the adapter. |
See adapter documentation |
filter-expression |
A filter expression such as full-text search, field comparisons, or a combination, where multiple terms are joined with AND, OR, or NOT See Filtering for a full description. |
No |
Some adapters require a time range to be specified in the read with either -from / -to or -last and/or may have additional constraints on the valid time ranges for a read operation. See the adapter documentation for details.
Example
read influxdb -from :1 hour ago: -to :now: -db 'test' name='cpu' AND host~=/www.*/
| reduce max() by host