skywalking-banyandb
Query Streams
Query operation queries the data in a stream.
bydbctl is the command line tool in examples.
The input contains two parts:
- Request: a YAML-based text which is defined by the API
- Time Range: YAML and CLI’s flags both support it.
Time Range
The query specification contains time_range field. The request should set absolute times to it.
bydbctl also provides start and end flags to support passing absolute and relative times.
“start” and “end” specify a time range during which the query is performed, they can be an absolute time like “2006-01-02T15:04:05Z07:00”, or relative time (to the current time) like “-30m”, or “30m”. They are both optional and their default values follow the rules below:
- when “start” and “end” are both absent, “start = now - 30 minutes” and “end = now”, namely past 30 minutes;
- when “start” is absent and “end” is present, this command calculates “start” (minus 30 units), e.g. “end = 2022-11-09T12:34:00Z”, so “start = end - 30 minutes = 2022-11-09T12:04:00Z”;
- when “start” is present and “end” is absent, this command calculates “end” (plus 30 units), e.g. “start = 2022-11-09T12:04:00Z”, so “end = start + 30 minutes = 2022-11-09T12:34:00Z”.
Examples
To retrieve elements in a stream named sw between 2022-10-15T22:32:48Z and 2022-10-15T23:32:48Z could use the below command. These elements also choose a tag trace_id which lives in a family named searchable and another tag data_binary belongs to family data.
$ bydbctl stream query -f - <<EOF
metadata:
group: "default"
name: "sw"
projection:
tagFamilies:
- name: "searchable"
tags: ["trace_id"]
- name: "data"
tags: ["data_binary"]
timeRange:
begin: 2022-10-15T22:32:48+08:00
end: 2022-10-15T23:32:48+08:00
EOF
The below command could query data in the last 30 minutes using relative time duration :
$ bydbctl stream query --start -30m -f - <<EOF
metadata:
group: "default"
name: "sw"
projection:
tagFamilies:
- name: "searchable"
tags: ["trace_id"]
- name: "data"
tags: ["data_binary"]
EOF