Titan 1.0 [Berkeley + ES] - ES索引的延迟更新 [英] Titan 1.0[Berkeley+ES] - Delayed update of ES index
问题描述
Titan 1.0 [Berkeley + Remote Elastic Search]
我们使用的是Titan的组合。以下是属性文件 -
storage.backend = berkeleyje
storage.directory = D：/ other-projects / graph-db / titan / enron-tk3 / db / berkeley
index.search.backend = elasticsearch
index.search.index-name = akshayatitan
index.search.hostname = localhost
index.search.elasticsearch.client-only = true
index.search.elasticsearch.local-mode = false
我们只使用混合索引。
现在我们通过Java代码添加几个属性的节点，然后获取它。
我们通过创建混合索引的属性来查询。
当我们通过键查询节点（一个混合索引是创建），我们不会立即得到节点。但是延迟后可以使用。
我们做错了什么？还是这个延迟更新的ES实例是预期的？
这是Java代码。
public static void main（String [] args）throws Exception {
GraphTest test = new GraphTest（）;
test.init（）;
Thread.sleep（10000）;
String emailId =emailId+ System.nanoTime（）;
test.createNode（emailId）;
System.out.println（创建+ emailId）;
System.out.println（First time+ test.getNode（emailId））;
Thread.sleep（2000）;
System.out.println（延迟2秒+ test.getNode（emailId））;
}
public void createNode（String emailid）{
顶点顶点= graph.addVertex（person）;
vertex.property（emailId，emailid）;
vertex.property（firstName，First Name）;
vertex.property（lastName，Last Name）;
vertex.property（address，Address）;
vertex.property（hometown，Noida）;
vertex.property（city，Noida）;
vertex.property（spousename，Preeti）;
graph.tx（）。commit（）;
}
public Object getNode（String emailId）{
Vertex vert = null;
String reString = null;
try {
vert = graph.traversal（）。V（）。has（emailId，emailId）.next（）;
reString = vert.value（emailId）;
} catch（NoSuchElementException e）{
e.printStackTrace（）;
} finally {
graph.tx（）。close（）;
}
return reString;
}
创建索引的代码是 -
private void createMixedIndexForVertexProperty（String indexName，String propertyKeyName，Class<？> propertyType）{
TitanManagement mgmt =（（TitanGraph）graph） .openManagement（）;
try {
PropertyKey propertyKey = makePropertyKey（propertyKeyName，propertyType，mgmt）;
TitanGraphIndex graphIndex = mgmt.getGraphIndex（indexName）;
if（graphIndex == null）{
graphIndex = mgmt.buildIndex（indexName，Vertex.class）
.addKey（propertyKey，Parameter.of（mapping，Mapping.STRING）） .buildMixedIndex（ 搜索）;
} else {
mgmt.addIndexKey（graphIndex，propertyKey）;
}
mgmt.commit（）;
} catch（Exception e）{
mgmt.rollback（）;
} finally {
}
}
public PropertyKey makePropertyKey（String propertyKeyName，Class<？> propertyType，TitanManagement mgmt）{
PropertyKey propertyKey = mgmt.getPropertyKey（propertyKeyName）;
if（propertyKey == null）{
propertyKey = mgmt.makePropertyKey（propertyKeyName）.dataType（String.class）.make（）;
}
return propertyKey;
}
public void init（）throws异常{
graph = TitanFactory
.open（new PropertiesConfiguration（new File（src / test / resources / titan- berkeleydb-es.properties）））;
createMixedIndexForVertexProperty（personnode，emailId，String.class）;
createMixedIndexForVertexProperty（personnode，firstName，String.class）;
createMixedIndexForVertexProperty（personnode，lastName，String.class）;
createMixedIndexForVertexProperty（personnode，address，String.class）;
createMixedIndexForVertexProperty（personnode，hometown，String.class）;
createMixedIndexForVertexProperty（personnode，city，String.class）;
createMixedIndexForVertexProperty（personnode，spousename，String.class）;
}
之前已经在 Titan邮件列表上讨论过。
$ b请注意，ES索引（ index.refresh_interval ）中有延迟。 您不能更新/插入一个值并立即查询。等待
至少1秒，然后再查询该值，否则结果可能是
为空。
你还应阅读Elasticsearch文档（修改您的数据和近实时搜索 ）索引行为：
弹性搜索在
附近实时提供数据操作和搜索功能。默认情况下，您可以从您索引/更新/删除数据的时间延迟一秒钟（刷新
间隔），直到出现在搜索结果中的
时间。这是一个重要的
与其他平台（如SQL）的区别，其中数据在事务完成后立即可用
。
注意
refresh_interval期望一段时间，例如1s（1秒）或2m（2
分钟）。一个绝对的数字，如1意味着1毫秒 - 一个确定的方式，
使您的集群跪下。
Titan 1.0 [Berkeley+ Remote Elastic Search] we are using this combination of Titan. Following is the properties file -
storage.backend=berkeleyje
storage.directory=D:/other-projects/graph-db/titan/enron-tk3/db/berkeley
index.search.backend=elasticsearch
index.search.index-name=akshayatitan
index.search.hostname=localhost
index.search.elasticsearch.client-only=true
index.search.elasticsearch.local-mode=false
We are only using Mixed Index.
Now we add a node with few properties through Java code and then fetch it.
We query by a property on which a mixed index is created.
When we query the node back by the key (one which mixed index is created) , we don't get the node immediately. However it get available after a delay.
What are we doing wrong ? Or is this delayed update of ES instance is expected?
Here is the Java code.
public static void main(String[] args) throws Exception {
GraphTest test = new GraphTest();
test.init();
Thread.sleep(10000);
String emailId = "emailId" + System.nanoTime();
test.createNode(emailId);
System.out.println("Create " + emailId);
System.out.println("First time " + test.getNode(emailId));
Thread.sleep(2000);
System.out.println("After a delay of 2 sec " + test.getNode(emailId));
}
public void createNode(String emailid) {
Vertex vertex = graph.addVertex("person");
vertex.property("emailId", emailid);
vertex.property("firstName", "First Name");
vertex.property("lastName", "Last Name");
vertex.property("address", "Address");
vertex.property("hometown", "Noida");
vertex.property("city", "Noida");
vertex.property("spousename", "Preeti");
graph.tx().commit();
}
public Object getNode(String emailId) {
Vertex vert = null;
String reString = null;
try {
vert = graph.traversal().V().has("emailId", emailId).next();
reString = vert.value("emailId");
} catch (NoSuchElementException e) {
e.printStackTrace();
} finally {
graph.tx().close();
}
return reString;
}
The code to create index is -
private void createMixedIndexForVertexProperty(String indexName, String propertyKeyName, Class<?> propertyType) {
TitanManagement mgmt = ((TitanGraph) graph).openManagement();
try {
PropertyKey propertyKey = makePropertyKey(propertyKeyName, propertyType, mgmt);
TitanGraphIndex graphIndex = mgmt.getGraphIndex(indexName);
if (graphIndex == null) {
graphIndex = mgmt.buildIndex(indexName, Vertex.class)
.addKey(propertyKey, Parameter.of("mapping", Mapping.STRING)).buildMixedIndex("search");
} else {
mgmt.addIndexKey(graphIndex, propertyKey);
}
mgmt.commit();
} catch (Exception e) {
mgmt.rollback();
} finally {
}
}
public PropertyKey makePropertyKey(String propertyKeyName, Class<?> propertyType, TitanManagement mgmt) {
PropertyKey propertyKey = mgmt.getPropertyKey(propertyKeyName);
if (propertyKey == null) {
propertyKey = mgmt.makePropertyKey(propertyKeyName).dataType(String.class).make();
}
return propertyKey;
}
public void init() throws Exception {
graph = TitanFactory
.open(new PropertiesConfiguration(new File("src/test/resources/titan-berkeleydb-es.properties")));
createMixedIndexForVertexProperty("personnode", "emailId", String.class);
createMixedIndexForVertexProperty("personnode", "firstName", String.class);
createMixedIndexForVertexProperty("personnode", "lastName", String.class);
createMixedIndexForVertexProperty("personnode", "address", String.class);
createMixedIndexForVertexProperty("personnode", "hometown", String.class);
createMixedIndexForVertexProperty("personnode", "city", String.class);
createMixedIndexForVertexProperty("personnode", "spousename", String.class);
}
This has been discussed before on the Titan mailing list.
note that there's a latency in ES indexing (
index.refresh_interval). You can't update / insert a value and immediately query it. Wait at least 1 second before you query the value, otherwise the result may be empty.
You should also read up on the Elasticsearch documentation (modifying your data and near real-time search) on the indexing behavior:
Elasticsearch provides data manipulation and search capabilities in near real time. By default, you can expect a one second delay (refresh interval) from the time you index/update/delete your data until the time that it appears in your search results. This is an important distinction from other platforms like SQL wherein data is immediately available after a transaction is completed.
CAUTION The
refresh_intervalexpects a duration such as1s(1 second) or2m(2 minutes). An absolute number like1means 1 millisecond--a sure way to bring your cluster to its knees.
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