Enhancement/performance optimizations

README.md

@@ -30,6 +30,7 @@
   * [4.3. Custom Serialization](#43-custom-serialization)
   * [4.4. Global Serialization](#44-global-serialization)
   * [4.5. JSON Serialization](#45-json-serialization)
+  * [4.6. String Serialization](#46-string-serialization)
 * [5. Setting Up Client Network](#5-setting-up-client-network)
   * [5.1. Providing Member Addresses](#51-providing-member-addresses)
   * [5.2. Setting Smart Routing](#52-setting-smart-routing)
@@ -1084,6 +1085,30 @@ config.serializationConfig.jsonStringDeserializationPolicy = JsonStringDeseriali
 }
 ```
 
+## 4.6. String Serialization
+
+Starting from version v3.12 Hazelcast Node.js client follows UTF-8 standard (RFC 3629) for string data type serialization of 4 byte UTF characters, like less common CJK characters and emoji. This may lead to compatibility issues with Hazelcast IMDG 3.x and other client libraries for string and JSON values. Such issues are represented by `Malformed byte sequence` (error code 64) errors on members and other clients.
+
+In case if you encounter these error messages, you can switch to the legacy mode of string serialization that provides full compatibility with Hazelcast IMDG 3.x members and other client libraries.
+
+Below is the configuration required to use the legacy string serialization.
+
+**Programmatic Configuration:**
+
+```javascript
+config.serializationConfig.stringSerializationPolicy = StringSerializationPolicy.LEGACY;
+```
+
+**Declarative Configuration:**
+
+```json
+{
+    "serialization": {
+        "stringSerializationPolicy": "legacy"
+    }
+}
+```
+
 # 5. Setting Up Client Network
 
 All network related configuration of Hazelcast Node.js client is performed via the `network` element in the declarative configuration file, or in the object `ClientNetworkConfig` when using programmatic configuration. Let's first give the examples for these two approaches. Then we will look at its sub-elements and attributes.

benchmark/MapGetRunner.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const REQ_COUNT = 10000;
+const BATCH_SIZE = 100;
+
+const Benchmark = require('./SimpleBenchmark');
+const Client = require('../.').Client;
+
+function randomString(len) {
+    const charSet = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
+    let res = '';
+    for (let i = 0; i < len; i++) {
+        const pos = Math.floor(Math.random() * charSet.length);
+        res += charSet.substring(pos, pos + 1);
+    }
+    return res;
+}
+
+const KEY = '00000000-0000-0000-0000-000000000000';
+const VAL = randomString(100 * 1024);
+
+Client.newHazelcastClient()
+    .then((client) => client.getMap('default'))
+    .then((map) => {
+        return map.set(KEY, VAL)
+            .then(() => map);
+    })
+    .then((map) => {
+        const benchmark = new Benchmark({
+            nextOp: () => map.get(KEY),
+            totalOpsCount: REQ_COUNT,
+            batchSize: BATCH_SIZE
+        });
+        return benchmark.run()
+            .then(() => map.destroy())
+            .then(() => map.client.shutdown());
+    })
+    .then(() => console.log('Benchmark finished'));

benchmark/README.md

@@ -2,6 +2,7 @@
 
 A collection of simple benchmarks that run operations on Map in parallel, measure execution time and calculate throughput:
 * `MapPutRunner` - runs `map.put('foo', 'bar')` operations.
+* `MapGetRunner` - runs `map.get` operations that read string value with >100 KB size.
 * `MapRandomOpRunner` - runs randomly selected operations (`get`, `put`, `remove`).
 
 ## Running the benchmark
@@ -21,7 +22,7 @@ Next, run at least one instance of IMDG. The most simple way to do it would be t
 docker run -p 5701:5701 hazelcast/hazelcast:3.11.2
 ```
 
-Finally, run the benchmark:
+Finally, run one of the benchmarks, e.g.:
 ```bash
 node benchmark/MapPutRunner.js
 ```

config-schema.json

@@ -164,6 +164,13 @@
                     ],
                     "default": "double"
                 },
+                "stringSerialization": {
+                    "enum": [
+                        "standard",
+                        "legacy"
+                    ],
+                    "default": "standard"
+                },
                 "isBigEndian": {
                     "type": "boolean",
                     "default": false

hazelcast-client-full.json

@@ -58,6 +58,7 @@
         "defaultNumberType": "double",
         "isBigEndian": true,
         "jsonStringDeserializationPolicy": "eager",
+        "stringSerialization": "standard",
         "dataSerializableFactories": [
             {
                 "path": "path/to/file",