Continuous Queries with the Go Client

Tip	The source code for this tutorial is available on GitHub.

This tutorial demonstrates how to register a continuous query on an Infinispan cache and receive real-time events when entries match an Ickle query predicate.

Prerequisites

A running Infinispan server.
Go 1.25 or later.

Running the Example

go run ./continuous-query

Code Walkthrough

Registering a Proto Schema

The example registers an InstaPost Protobuf schema with id, user, and hashtag fields.

client.Schemas().Register(ctx, "instapost.proto", instaPostProto)

Setting Up the Continuous Query

A continuous query filters posts by a specific user. The CQJoining event fires each time a matching entry is inserted.

cq, err := cache.ContinuousQuery(ctx,
    "FROM tutorial.InstaPost p WHERE p.user = :userName",
    hotrod.WithCQParam("userName", "belen_esteban"),
)

Consuming Events

Events are consumed from the cq.Events channel in a goroutine.

for event := range cq.Events {
    if event.Type == hotrod.CQJoining {
        // handle matching entry
    }
}

Generating Data

The example inserts 100 random posts from a pool of users and hashtags. Posts by belen_esteban trigger continuous query events.

Expected Output

Registered instapost.proto schema.
Continuous query registered.
@belen_esteban has posted again! Hashtag: #love
@belen_esteban has posted again! Hashtag: #infinispan
...

Total posts: 100
Total posts by @belen_esteban: <varies>