#984 update Ambassador readme

This commit is contained in:
Ilkka Seppälä
2019-11-11 22:03:44 +02:00
parent c4418311c6
commit 329479dda0
2 changed files with 46 additions and 52 deletions

View File

@ -74,53 +74,50 @@ A service ambassador adding additional features such as logging, latency checks
```java ```java
public class ServiceAmbassador implements RemoteServiceInterface { public class ServiceAmbassador implements RemoteServiceInterface {
private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class); private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
private static final int RETRIES = 3; private static final int RETRIES = 3;
private static final int DELAY_MS = 3000; private static final int DELAY_MS = 3000;
ServiceAmbassador() {} ServiceAmbassador() {
}
@Override @Override
public long doRemoteFunction(int value) { public long doRemoteFunction(int value) {
return safeCall(value);
}
return safeCall(value); private long checkLatency(int value) {
} var startTime = System.currentTimeMillis();
var result = RemoteService.getRemoteService().doRemoteFunction(value);
var timeTaken = System.currentTimeMillis() - startTime;
private long checkLatency(int value) { LOGGER.info("Time taken (ms): " + timeTaken);
RemoteService service = RemoteService.getRemoteService(); return result;
long startTime = System.currentTimeMillis(); }
long result = service.doRemoteFunction(value);
long timeTaken = System.currentTimeMillis() - startTime;
LOGGER.info("Time taken (ms): " + timeTaken); private long safeCall(int value) {
return result; var retries = 0;
} var result = (long) FAILURE;
private long safeCall(int value) { for (int i = 0; i < RETRIES; i++) {
if (retries >= RETRIES) {
return FAILURE;
}
int retries = 0; if ((result = checkLatency(value)) == FAILURE) {
long result = -1; LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
retries++;
for (int i = 0; i < RETRIES; i++) { try {
sleep(DELAY_MS);
if (retries >= RETRIES) { } catch (InterruptedException e) {
return -1; LOGGER.error("Thread sleep state interrupted", e);
}
if ((result = checkLatency(value)) == -1) {
LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
retries++;
try {
sleep(DELAY_MS);
} catch (InterruptedException e) {
LOGGER.error("Thread sleep state interrupted", e);
}
} else {
break;
}
} }
return result; } else {
break;
}
} }
return result;
}
} }
``` ```
@ -129,17 +126,14 @@ A client has a local service ambassador used to interact with the remote service
```java ```java
public class Client { public class Client {
private ServiceAmbassador serviceAmbassador; private static final Logger LOGGER = LoggerFactory.getLogger(Client.class);
private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
Client() { long useService(int value) {
serviceAmbassador = new ServiceAmbassador(); var result = serviceAmbassador.doRemoteFunction(value);
} LOGGER.info("Service result: " + result);
return result;
long useService(int value) { }
long result = serviceAmbassador.doRemoteFunction(value);
LOGGER.info("Service result: " + result);
return result;
}
} }
``` ```
@ -148,8 +142,8 @@ And here are two clients using the service.
```java ```java
public class App { public class App {
public static void main(String[] args) { public static void main(String[] args) {
Client host1 = new Client(); var host1 = new Client();
Client host2 = new Client(); var host2 = new Client();
host1.useService(12); host1.useService(12);
host2.useService(73); host2.useService(73);
} }

View File

@ -45,8 +45,8 @@ public class App {
* Entry point. * Entry point.
*/ */
public static void main(String[] args) { public static void main(String[] args) {
Client host1 = new Client(); var host1 = new Client();
Client host2 = new Client(); var host2 = new Client();
host1.useService(12); host1.useService(12);
host2.useService(73); host2.useService(73);
} }