GitHub user asdf2014 opened a pull request: https://github.com/apache/zookeeper/pull/303
ZOOKEEPER-2840: Should using `System.nanoTime() ^ this.hashCode()` fo⦠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--; } } ``` You can merge this pull request into a Git repository by running: $ git pull https://github.com/asdf2014/zookeeper ZOOKEEPER-2840 Alternatively you can review and apply these changes as the patch at: https://github.com/apache/zookeeper/pull/303.patch To close this pull request, make a commit to your master/trunk branch with (at least) the following in the commit message: This closes #303 ---- commit dad9cdba24c825a56dfe94a277ea4232af429bdb Author: asdf2014 <1571805...@qq.com> Date: 2017-07-05T12:17:44Z ZOOKEEPER-2840: Should using `System.nanoTime() ^ this.hashCode()` for StaticHostProvider ---- --- If your project is set up for it, you can reply to this email and have your reply appear on GitHub as well. 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