cluster()
Applies to: ✅ Azure Data Explorer
Changes the reference of the query to a remote cluster. To access a database within the same cluster, use the database() function. For more information, see cross-database and cross-cluster queries.
Syntax
cluster(name)
Learn more about syntax conventions.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
| name | string |
✔️ | The name of the cluster to reference. The value can be specified as a fully qualified domain name, or the name of the cluster without the .kusto.chinacloudapi.cn suffix. The cluster name is treated as case-insenstive and the recommendation is to provide it lower-case. The value can't be the result of subquery evaluation. |
Examples
Use cluster() to access remote cluster
The following query can be run on any cluster.
cluster('help').database('Samples').StormEvents | count
cluster('help.chinaeast2.kusto.chinacloudapi.cn').database('Samples').StormEvents | count
Output
| Count |
|---|
| 59066 |
Use cluster() inside let statements
The previous query can be rewritten to use a query-defined function (let statement) that takes a parameter called clusterName and passes it to the cluster() function.
let foo = (clusterName:string)
{
cluster(clusterName).database('Samples').StormEvents | count
};
foo('help')
Output
| Count |
|---|
| 59066 |
Use cluster() inside Functions
The same query as above can be rewritten to be used in a function that receives a parameter clusterName - which is passed into the cluster() function.
.create function foo(clusterName:string)
{
cluster(clusterName).database('Samples').StormEvents | count
};
Note
Stored functions using the cluster() function can't be used in cross-cluster queries.