Goal: Perform the Advanced REPLACE operation where Eventing interacts with the Data service.
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This function advancedReplaceOp merely demonstrates the Advanced REPLACE operation.
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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 === "control_adv_replace".
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Always tries to insert the test document, any insert error will be ignored.
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There are 3 modes of operation: no_cas, bad_cas, and good_cas.
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For more information refer to Advanced REPLACE operation in the detailed documentation.
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advancedReplaceOp
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Input Data/Mutation
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Output Data
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Output Log
// To run configure the settings for this Function, advancedReplaceOp, as follows:
//
// 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 we have our 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") {
// Here we pass no CAS it will always succeed
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") {
// Here we pass a non-matching CAS it will always fail
new_meta = {"id":"test_adv_replace:" + doc.ins_id, "cas":"1111111111111111111"};
}
if (doc.mode && doc.mode === "good_cas") {
// Here we will pass the matching or current CAS it will succeed
var tmp_r = couchbase.get(src_col,{"id":"test_adv_replace:" + doc.ins_id});
if (tmp_r.success) {
// Here we use the current CAS just 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"
}We try to replace three (3) documents the first and last replacements succeed but the second, fails because of a CAS missmatch.
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
}