Question

如何从aerospike命名空间获取所有密钥，就像我可以使用map.keyset从地图中获取密钥一样。我浏览了这个链接Aerospike: how do I get record key?。我做了答案中被告知的事情。我用writePolicy.sendKey = true编写了代码，但是当我在NULL功能中显示密钥时，我仍然得到scanCallback。

这是我编写记录的代码（任何帮助都会受到赞赏）

def writeToAerospike(): Boolean = {

val host:Host = new Host("xx.xxx.xxx.xx", 3000)
val client = new AerospikeClient(new ClientPolicy,host)

val policy = new WritePolicy();
policy.sendKey = true;
policy.timeout = 50000;

if(client.isConnected()){
   println("connection to aerospike client sucessful")
   client.put(policy,new Key("test", "testSet", "1"),new Bin("name", "john"))

   //verify if the record is entered correctly
   println(client.get(policy,new Key("test", "testing", "1")).getValue("name"))

   client.close()
   return true
}
return false 
}

我使用此示例中的代码扫描记录：http://www.aerospike.com/docs/client/java/usage/scan/scan.html

class ScanParallelTest extends ScanCallback {

  private var recordCount: Int = _

  def runTest() {
    val client = new AerospikeClient("xxx.xx.xxx.xx", 3000)
    try {
      val policy = new ScanPolicy()
      policy.concurrentNodes = true
      policy.priority = Priority.LOW
      policy.includeBinData = true
      client.scanAll(policy, "test", "testSet", this)
      println("Records " + recordCount)
    } finally {
      client.close()
   }
 }

 def scanCallback(key: Key, record: Record) {
   recordCount += 1

   println("Records " + recordCount )
   println ("key=" + " "+key.userKey.toString() +" and "+" record: "+" "+ record.bins)
  }
}

以下是我遇到的错误：

com.aerospike.client.AerospikeException: java.lang.NullPointerException
    at com.aerospike.client.command.ScanExecutor.scanParallel(ScanExecutor.java:66)
    at com.aerospike.client.AerospikeClient.scanAll(AerospikeClient.java:551)
    at aerospike.asd.ScanParallelTest.runTest(ScanParallelTest.scala:23)
    at aerospike.asd.test$.main(test.scala:10)
    at aerospike.asd.test.main(test.scala)

Caused by: java.lang.NullPointerException
    at aerospike.asd.ScanParallelTest.scanCallback(ScanParallelTest.scala:35)
    at com.aerospike.client.command.ScanCommand.parseRecordResults(ScanCommand.java:122)
    at com.aerospike.client.command.MultiCommand.parseResult(MultiCommand.java:58)
    at com.aerospike.client.command.SyncCommand.execute(SyncCommand.java:56)
    at com.aerospike.client.command.ScanExecutor$ScanThread.run(ScanExecutor.java:134)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

我尝试将client.readPolicyDefault.sendKey = true;和client.scanPolicyDefault.sendKey = true;与client.writePolicyDefault.sendKey = true;一起使用，代码开始返回原始密钥而不是NULL。

以下是helipilot50的工作代码链接：https://github.com/helipilot50/store-primary-key

这对我的情况很有帮助。谢谢！

Answer 2

添加法赫德的答案：

请记住，存储密钥（而不仅仅是摘要）会占用空间。如果你的密钥是100个字符的字符串而你的记录是两个8字节的整数，那么密钥存储将使用比这两个值更多的空间。

善用这些知识而不是邪恶：）

如何从命名空间获取所有密钥？

2 个答案: