Function: Advanced GET operation (with cache)
Couchbase Server 7.0.2 Goal: Perform the Advanced GET operation where Eventing interacts with the Data service.
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This function advancedGetOpWithCache merely demonstrates the Advanced GET operation with Bucket Backed Cache enabled.
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Requires Eventing Storage (or metadata collection) and a "source" collection.
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Needs a Binding of type "bucket alias" (as documented in the Scriptlet).
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Will operate on any mutation where doc.type === "test_adv_get".
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The optional third parameter to couchbase.get of {"cache": true} enables caching of documents for up to 1 second.
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This RYOW caching is 18X-25X faster than reading near static data directly from the Data Service (or KV).
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For more information refer to Advanced GET operation in the detailed documentation.
// To run configure the settings for this Function, advancedGetOpWithCache, as follows:
//
// Version 7.1+
// "Function Scope"
// *.* (or try bulk.data if non-privileged)
// Version 7.0.2+
// "Listen to Location"
// bulk.data.source
// "Eventing Storage"
// rr100.eventing.metadata
// Binding(s)
// 1. "binding type", "alias name...", "bucket.scope.collection", "Access"
// "bucket alias", "src_col", "bulk.data.source", "read and write"
function OnUpdate(doc, meta) {
// filter out non-intersting documents
if (!doc.type || doc.type !== "test_adv_get") return;
log('input doc ', doc);
log('input meta', meta);
// let's read the same item and then try to read a non existent item
var meta_ary = [{"id":"test_adv_get::1"}, {"id":"not_present::1"}];
for (var i = 0; i < meta_ary.length; i++) {
var result = couchbase.get(src_col,meta_ary[i],{"cache": true});
if (result.success) {
log('success adv. get with cache: result',result);
} else {
log('failure adv. get with cache: id',meta_ary[i].id,'result',result);
}
}
}
INPUT: KEY test_adv_get::1
{
"id": 1,
"type": "test_adv_get"
}
2021-10-04T15:54:31.101-07:00 [INFO] "input doc " {
"id": 1,
"type": "test_adv_get"
}
2021-10-04T15:54:31.101-07:00 [INFO] "input meta" {
"cas": "1633388049399873536",
"id": "test_adv_get::1",
"expiration": 0,
"flags": 33554438,
"vb": 324,
"seq": 3,
"datatype": "json"
}
2021-10-04T15:54:31.102-07:00 [INFO] "success adv. get with cache: result" {
"doc": {
"id": 1,
"type": "test_adv_get"
},
"meta": {
"id": "test_adv_get::1",
"cas": "1633388049399873536",
"datatype": "json"
},
"success": true
}
2021-10-04T15:54:31.102-07:00 [INFO] "failure adv. get with cache: id" "not_present::1" "result" {
"error": {
"code": 1,
"name": "LCB_KEY_ENOENT",
"desc": "The document key does not exist on the server",
"key_not_found": true
},
"success": false
}