Function: Advanced DELETE Operation

Enterprise Edition

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

The advancedDeleteOp function:

Performs the Advanced DELETE 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_delete"
Always tries to insert the test document and ignores insert errors
Has 4 modes of operation: no_cas, bad_cas, good_cas, and no_key

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

advancedDeleteOp
Input data
Output data

// Configure the settings for the advancedDeleteOp 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_delete")) return;

    log('input meta', meta);
    log('input doc ', doc);

    // Setup, make sure there is a doc to "delete", ignore any errors
    couchbase.insert(src_col,{"id":"test_adv_delete:" + 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_delete:" + doc.ins_id};
    }
    if (doc.mode && doc.mode === "bad_cas") {
        // Pass a non-matching CAS - it always fails
        new_meta = {"id":"test_adv_delete:" + 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_delete:" + doc.ins_id});
        if (tmp_r.success) {
            // Use the current CAS to read via couchbase.get(...)
            new_meta = {"id":"test_adv_delete:" + doc.ins_id, "cas": tmp_r.meta.cas};
        } else {
            log('Cannot delete due to no such key',"test_adv_delete:" + doc.ins_id);
            return;
        }
    }
    if (doc.mode && doc.mode === "no_key") {
        // Remove (delete with a basic bucket op) so that we have: no such key
        delete src_col["test_adv_delete:" + doc.ins_id]
        new_meta = {"id":"test_adv_delete:" + doc.ins_id};
    }
    var result = couchbase.delete(src_col,new_meta);
    if (result.success) {
        log('success adv. delete: result',result);
    } else {
        log('failure adv. delete: id',new_meta.id,'result',result);
    }
}

Mutation #1

INPUT: KEY control_adv_delete::1

{
  "id": 1,
  "type": "control_adv_delete",
  "ins_id": 10,
  "mode": "no_cas"
}

Mutation #2

INPUT: KEY control_adv_delete::2

{
  "id": 2,
  "type": "control_adv_delete",
  "ins_id": 10,
  "mode": "bad_cas"
}

Mutation #3

INPUT: KEY control_adv_delete::3

{
  "id": 3,
  "type": "control_adv_delete",
  "ins_id": 10,
  "mode": "no_key"
}

Mutation #4

INPUT: KEY control_adv_delete::4

{
  "id": 4,
  "type": "control_adv_delete",
  "ins_id": 10,
  "mode": "good_cas"
}

Perform 4 deletion attempts. The second attempt fails because of a CAS mismatch. The third attempt fails because the document key does not exist.

Logs from Mutation #1

2021-01-08T11:45:02.897-08:00 [INFO] "input meta"
{
    "cas": "1610134800219308032",
    "id": "control_adv_delete::1",
    "expiration": 0,
    "flags": 33554438,
    "vb": 221,
    "seq": 1
}
2021-01-08T11:45:02.898-08:00 [INFO] "input doc "
{
    "id": 1,
    "type": "control_adv_delete",
    "ins_id": 10,
    "mode": "no_cas"
}
2021-01-08T11:45:02.899-08:00 [INFO] "success adv. delete: result"
{
    "meta": {
        "id": "test_adv_delete:10",
        "cas": "1610135102898962432"
    },
    "success": true
}

Logs from Mutation #2

2021-01-08T11:46:11.225-08:00 [INFO] "input meta"
{
    "cas": "1610135171148152832",
    "id": "control_adv_delete::2",
    "expiration": 0,
    "flags": 33554438,
    "vb": 468,
    "seq": 3
}
2021-01-08T11:46:11.225-08:00 [INFO] "input doc "
{
    "id": 2,
    "type": "control_adv_delete",
    "ins_id": 10,
    "mode": "bad_cas"
}
2021-01-08T11:46:11.228-08:00 [INFO] "failure adv. delete: id" "test_adv_delete: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

2021-01-08T11:52:51.520-08:00 [INFO] "input meta"
{
    "cas": "1610135571485425664",
    "id": "control_adv_delete::3",
    "expiration": 0,
    "flags": 33554438,
    "vb": 723,
    "seq": 5
}
2021-01-08T11:52:51.520-08:00 [INFO] "input doc "
{
    "id": 3,
    "type": "control_adv_delete",
    "ins_id": 10,
    "mode": "no_key"
}
2021-01-08T11:52:51.522-08:00 [INFO] "failure adv. delete: id" "test_adv_delete:10" "result"
{
    "error": {
        "code": 272,
        "name": "LCB_KEY_ENOENT",
        "desc": "The document key does not exist on the server",
        "key_not_found": true
    },
    "success": false
}

Logs from Mutation #4

2021-01-08T11:53:36.070-08:00 [INFO] "input meta"
{
    "cas": "1610135616063602688",
    "id": "control_adv_delete::4",
    "expiration": 0,
    "flags": 33554438,
    "vb": 183,
    "seq": 3
}
2021-01-08T11:53:36.070-08:00 [INFO] "input doc "
{
    "id": 4,
    "type": "control_adv_delete",
    "ins_id": 10,
    "mode": "good_cas"
}
2021-01-08T11:53:36.074-08:00 [INFO] "success adv. delete: result"
{
    "meta": {
        "id": "test_adv_delete:10",
        "cas": "1610135616073760768"
    },
    "success": true
}