Function: Advanced REPLACE Operation

      +

      Perform the Advanced REPLACE operation where Eventing interacts with the Data Service.

      The advancedReplaceOp function:

      • Performs the Advanced REPLACE operation

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

      • Requires a binding of type bucket alias

      • Operates on any mutation where doc.type === "control_adv_replace"

      • Always tries to insert the test document and ignores insert errors

      • Has 3 modes of operation: no_cas, bad_cas, and good_cas

      For more information about the Advanced Self-Recursion Parameter, see Advanced REPLACE Operation.

      • advancedReplaceOp

      • Input data

      • Output data

      • Output log

      // Configure the settings for the advancedReplaceOp function as follows:
      //
      // Version 7.1+
      //   "Function Scope"
      //     *.* (or try bulk.data if non-privileged)
      // Version 7.0+
      //   "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"
      //
      // Version 6.6.1
      //   "Source Bucket"
      //     source
      //   "MetaData Bucket"
      //     metadata
      //   Binding(s)
      //    1. "binding type", "alias name...", "bucket",     "Access"
      //       "bucket alias", "src_col",       "source",     "read and write"
      
      function OnUpdate(doc, meta) {
          if (!meta.id.startsWith("control_adv_replace")) return;
      
          log('input meta', meta);
          log('input doc ', doc);
      
          // Setup, make sure there is a doc to "replace", ignore any errors
          couchbase.insert(src_col,{"id":"test_adv_replace:" + doc.ins_id},{"a:": 1});
      
          var new_meta;
          if (doc.mode && doc.mode === "no_cas") {
              // No CAS is passed - it always succeeds
              new_meta = {"id":"test_adv_replace:" + doc.ins_id};
              // (Optional) Set an expiry 60 seconds in the future
              // new_meta.expiry_date = new Date(Date.now() + 60 * 1000);
          }
          if (doc.mode && doc.mode === "bad_cas") {
              // Pass a non-matching CAS - it always fails
              new_meta = {"id":"test_adv_replace:" + doc.ins_id, "cas":"1111111111111111111"};
          }
          if (doc.mode && doc.mode === "good_cas") {
              // Pass the matching or current CAS - it succeeds
              var tmp_r = couchbase.get(src_col,{"id":"test_adv_replace:" + doc.ins_id});
              if (tmp_r.success) {
                  // Use the current CAS to read via couchbase.get(...)
                  new_meta = {"id":"test_adv_replace:" + doc.ins_id, "cas": tmp_r.meta.cas};
              } else {
                  log('Cannot replace due to no such key',"test_adv_replace:" + doc.ins_id);
                  return;
              }
          }
          var new_doc = {id: doc.ins_id, type: "test_adv_replace", random: Math.random()};
          var result = couchbase.replace(src_col,new_meta,new_doc);
          if (result.success) {
              log('success adv. replace: result',result);
          } else {
              log('failure adv. replace: id',new_meta.id,'result',result);
          }
      }
      Mutation #1
      
      INPUT: KEY control_adv_replace::1
      
      {
        "id": 1,
        "type": "control_adv_replace",
        "ins_id": 10,
        "mode": "no_cas"
      }
      
      Mutation #2
      
      INPUT: KEY control_adv_replace::2
      
      {
        "id": 2,
        "type": "control_adv_replace",
        "ins_id": 10,
        "mode": "bad_cas"
      }
      
      Mutation #3
      
      INPUT: KEY control_adv_replace::3
      
      {
        "id": 3,
        "type": "control_adv_replace",
        "ins_id": 10,
        "mode": "good_cas"
      }

      Replace 3 documents. The first and last replacements are successful; the second replacement fails because of a CAS mismatch.

      KEY: test_adv_replace:10
      
      {
        "id": 10,
        "type": "test_adv_replace",
        "random": 0.40223830137164085
      }
      Logs from Mutation #1
      
      2021-01-08T10:58:39.846-08:00 [INFO] "input meta"
      {
          "cas": "1610131902064820224",
          "id": "control_adv_replace::1",
          "expiration": 0,
          "flags": 33554438,
          "vb": 417,
          "seq": 4
      }
      2021-01-08T10:58:39.846-08:00 [INFO] "input doc "
      {
          "id": 1,
          "type": "control_adv_replace",
          "ins_id": 10,
          "mode": "no_cas"
      }
      2021-01-08T10:58:39.847-08:00 [INFO] "success adv. replace: result"
      {
          "meta": {
              "id": "test_adv_replace:10",
              "cas": "1610132319847055360"
          },
          "success": true
      }
      
      Logs from Mutation #2
      
      2021-01-08T10:59:04.151-08:00 [INFO] "input meta"
      {
          "cas": "1610132344113397760",
          "id": "control_adv_replace::2",
          "expiration": 0,
          "flags": 33554438,
          "vb": 168,
          "seq": 3
      }
      2021-01-08T10:59:04.151-08:00 [INFO] "input doc "
      {
          "id": 2,
          "type": "control_adv_replace",
          "ins_id": 10,
          "mode": "bad_cas"
      }
      2021-01-08T10:59:04.154-08:00 [INFO] "failure adv. replace: id" "test_adv_replace:10" "result"
      {
          "error": {
              "code": 272,
              "name": "LCB_KEY_EEXISTS",
              "desc": "The document key exists with a CAS value different than specified",
              "cas_mismatch": true
          },
          "success": false
      }
      
      Logs from Mutation #3
      
      2021-01-08T10:59:35.692-08:00 [INFO] "input meta"
      {
          "cas": "1610132375634706432",
          "id": "control_adv_replace::3",
          "expiration": 0,
          "flags": 33554438,
          "vb": 943,
          "seq": 3
      }
      2021-01-08T10:59:35.692-08:00 [INFO] "input doc "
      {
          "id": 3,
          "type": "control_adv_replace",
          "ins_id": 10,
          "mode": "good_cas"
      }
      2021-01-08T10:59:35.696-08:00 [INFO] "success adv. replace: result"
      {
          "meta": {
              "id": "test_adv_replace:10",
              "cas": "1610132375695589376"
          },
          "success": true
      }