A newer version of this documentation is available.

View Latest

Function: Advanced GET operation (with cache)

      +

      Couchbase Server 7.0.2 Goal: Perform the Advanced GET operation where Eventing interacts with the Data service.

      • This function advancedGetOpWithCache merely demonstrates the Advanced GET operation with Bucket Backed Cache enabled.

      • Requires Eventing Storage (or metadata collection) and a "source" collection.

      • Needs a Binding of type "bucket alias" (as documented in the Scriptlet).

      • Will operate on any mutation where doc.type === "test_adv_get".

      • The optional third parameter to couchbase.get of {"cache": true} enables caching of documents for up to 1 second.

      • This RYOW caching is 18X-25X faster than reading near static data directly from the Data Service (or KV).

      • For more information refer to Advanced GET operation in the detailed documentation.

      • advancedGetOpWithCache

      • Input Data/Mutation

      • Output Data/Logged

      // 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
      }