Benedict Jin created ZOOKEEPER-2840:
---------------------------------------
Summary: Should using `System.nanoTime() ^ this.hashCode()` for
StaticHostProvider
Key: ZOOKEEPER-2840
URL: https://issues.apache.org/jira/browse/ZOOKEEPER-2840
Project: ZooKeeper
Issue Type: Bug
Components: java client
Affects Versions: 3.5.3
Reporter: Benedict Jin
Assignee: Benedict Jin
Should using `System.nanoTime() ^ this.hashCode()` for StaticHostProvider
instead of `System.currentTimeMillis()`. Because if we have three Zookeeper
server nodes and set the `zookeeper.leaderServes` as `no`, then those
connections from client will always connect with the first Zookeeper server
node. Due to...
```java
@Test
public void testShuffle() throws Exception {
LinkedList<InetSocketAddress> inetSocketAddressesList = new
LinkedList<>();
inetSocketAddressesList.add(new InetSocketAddress(0));
inetSocketAddressesList.add(new InetSocketAddress(1));
inetSocketAddressesList.add(new InetSocketAddress(2));
/*
1442045361
currentTime: 1499253530044, currentTime ^ hashCode: 1500143845389,
Result: 1 2 0
currentTime: 1499253530044, currentTime ^ hashCode: 1500143845389,
Result: 2 0 1
currentTime: 1499253530045, currentTime ^ hashCode: 1500143845388,
Result: 0 1 2
currentTime: 1499253530045, currentTime ^ hashCode: 1500143845388,
Result: 1 2 0
currentTime: 1499253530046, currentTime ^ hashCode: 1500143845391,
Result: 1 2 0
currentTime: 1499253530046, currentTime ^ hashCode: 1500143845391,
Result: 1 2 0
currentTime: 1499253530046, currentTime ^ hashCode: 1500143845391,
Result: 1 2 0
currentTime: 1499253530046, currentTime ^ hashCode: 1500143845391,
Result: 1 2 0
currentTime: 1499253530047, currentTime ^ hashCode: 1500143845390,
Result: 1 2 0
currentTime: 1499253530047, currentTime ^ hashCode: 1500143845390,
Result: 1 2 0
*/
internalShuffleMillis(inetSocketAddressesList);
/*
146611050
currentTime: 22618159623770, currentTime ^ hashCode: 22618302559536,
Result: 2 1 0
currentTime: 22618159800738, currentTime ^ hashCode: 22618302085832,
Result: 0 1 2
currentTime: 22618159967442, currentTime ^ hashCode: 22618302248888,
Result: 1 0 2
currentTime: 22618160135080, currentTime ^ hashCode: 22618302013634,
Result: 2 1 0
currentTime: 22618160302095, currentTime ^ hashCode: 22618301535077,
Result: 2 1 0
currentTime: 22618160490260, currentTime ^ hashCode: 22618301725822,
Result: 1 0 2
currentTime: 22618161566373, currentTime ^ hashCode: 22618300303823,
Result: 1 0 2
currentTime: 22618161745518, currentTime ^ hashCode: 22618300355844,
Result: 2 1 0
currentTime: 22618161910357, currentTime ^ hashCode: 22618291603775,
Result: 2 1 0
currentTime: 22618162079549, currentTime ^ hashCode: 22618291387479,
Result: 0 1 2
*/
internalShuffleNano(inetSocketAddressesList);
inetSocketAddressesList.clear();
inetSocketAddressesList.add(new InetSocketAddress(0));
inetSocketAddressesList.add(new InetSocketAddress(1));
/*
415138788
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530050, currentTime ^ hashCode: 1499124456998,
Result: 0 1
currentTime: 1499253530053, currentTime ^ hashCode: 1499124456993,
Result: 0 1
currentTime: 1499253530055, currentTime ^ hashCode: 1499124456995,
Result: 0 1
currentTime: 1499253530055, currentTime ^ hashCode: 1499124456995,
Result: 0 1
currentTime: 1499253530055, currentTime ^ hashCode: 1499124456995,
Result: 0 1
*/
internalShuffleMillis(inetSocketAddressesList);
/*
13326370
currentTime: 22618168292396, currentTime ^ hashCode: 22618156149774,
Result: 1 0
currentTime: 22618168416181, currentTime ^ hashCode: 22618156535703,
Result: 1 0
currentTime: 22618168534056, currentTime ^ hashCode: 22618156432394,
Result: 0 1
currentTime: 22618168666548, currentTime ^ hashCode: 22618155774358,
Result: 0 1
currentTime: 22618168818946, currentTime ^ hashCode: 22618155623712,
Result: 0 1
currentTime: 22618168936821, currentTime ^ hashCode: 22618156011863,
Result: 1 0
currentTime: 22618169056251, currentTime ^ hashCode: 22618155893721,
Result: 1 0
currentTime: 22618169611103, currentTime ^ hashCode: 22618157370237,
Result: 1 0
currentTime: 22618169744528, currentTime ^ hashCode: 22618156713138,
Result: 1 0
currentTime: 22618171273170, currentTime ^ hashCode: 22618184562672,
Result: 1 0
*/
internalShuffleNano(inetSocketAddressesList);
}
private void internalShuffleMillis(LinkedList<InetSocketAddress>
inetSocketAddressesList) throws Exception {
int hashCode = new
StaticHostProvider(inetSocketAddressesList).hashCode();
System.out.println(hashCode);
int count = 10;
Random r;
while (count > 0) {
long currentTime = System.currentTimeMillis();
r = new Random(currentTime ^ hashCode);
System.out.print(String.format("currentTime: %s, currentTime ^
hashCode: %s, Result: ",
currentTime, currentTime ^ hashCode));
Collections.shuffle(inetSocketAddressesList, r);
for (InetSocketAddress inetSocketAddress : inetSocketAddressesList)
{
System.out.print(String.format("%s ",
inetSocketAddress.getPort()));
}
System.out.println();
count--;
}
}
private void internalShuffleNano(LinkedList<InetSocketAddress>
inetSocketAddressesList) throws Exception {
int hashCode = new
StaticHostProvider(inetSocketAddressesList).hashCode();
System.out.println(hashCode);
int count = 10;
Random r;
while (count > 0) {
long currentTime = System.nanoTime();
r = new Random(currentTime ^ hashCode);
System.out.print(String.format("currentTime: %s, currentTime ^
hashCode: %s, Result: ",
currentTime, currentTime ^ hashCode));
Collections.shuffle(inetSocketAddressesList, r);
for (InetSocketAddress inetSocketAddress : inetSocketAddressesList)
{
System.out.print(String.format("%s ",
inetSocketAddress.getPort()));
}
System.out.println();
count--;
}
}
```
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