org.apache.solr.client.solrj.impl

Class LBHttpSolrClient

java.lang.Object

org.apache.solr.client.solrj.SolrClient

org.apache.solr.client.solrj.impl.LBSolrClient

org.apache.solr.client.solrj.impl.LBHttpSolrClient

All Implemented Interfaces:

Closeable, Serializable, AutoCloseable

public class LBHttpSolrClient
extends LBSolrClient

LBHttpSolrClient or "LoadBalanced HttpSolrClient" is a load balancing wrapper around HttpSolrClient. This is useful when you have multiple Solr servers and the requests need to be Load Balanced among them. Do NOT use this class for indexing in leader/follower scenarios since documents must be sent to the correct leader; no inter-node routing is done. In SolrCloud (leader/replica) scenarios, it is usually better to use CloudSolrClient, but this class may be used for updates because the server will forward them to the appropriate leader.

It offers automatic failover when a server goes down and it detects when the server comes back up.

Load balancing is done using a simple round-robin on the list of servers.

If a request to a server fails by an IOException due to a connection timeout or read timeout then the host is taken off the list of live servers and moved to a 'dead server list' and the request is resent to the next live server. This process is continued till it tries all the live servers. If at least one server is alive, the request succeeds, and if not it fails.

 SolrClient lbHttpSolrClient = new LBHttpSolrClient("http://host1:8080/solr/", "http://host2:8080/solr", "http://host2:8080/solr");
 //or if you wish to pass the HttpClient do as follows
 httpClient httpClient = new HttpClient();
 SolrClient lbHttpSolrClient = new LBHttpSolrClient(httpClient, "http://host1:8080/solr/", "http://host2:8080/solr", "http://host2:8080/solr");
 

This detects if a dead server comes alive automatically. The check is done in fixed intervals in a dedicated thread. This interval can be set using LBSolrClient.setAliveCheckInterval(int) , the default is set to one minute.

When to use this?
This can be used as a software load balancer when you do not wish to setup an external load balancer. Alternatives to this code are to use a dedicated hardware load balancer or using Apache httpd with mod_proxy_balancer as a load balancer. See Load balancing on Wikipedia

Since:

solr 1.4

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	LBHttpSolrClient.Builder Constructs LBHttpSolrClient instances from provided configuration.
static class	LBHttpSolrClient.Req Deprecated. use LBSolrClient.Req instead
static class	LBHttpSolrClient.Rsp Deprecated. use LBSolrClient.Rsp instead

Nested classes/interfaces inherited from class org.apache.solr.client.solrj.impl.LBSolrClient

LBSolrClient.ServerWrapper

Field Summary

Fields inherited from class org.apache.solr.client.solrj.impl.LBSolrClient

parser, queryParams, requestWriter

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	LBHttpSolrClient(org.apache.http.client.HttpClient httpClient, ResponseParser parser, String... solrServerUrl) Deprecated. use LBHttpSolrClient(Builder) instead, as it is a more extension/subclassing-friendly alternative
protected	LBHttpSolrClient(HttpSolrClient.Builder httpSolrClientBuilder, org.apache.http.client.HttpClient httpClient, String... solrServerUrl) Deprecated. use LBHttpSolrClient(Builder) instead, as it is a more extension/subclassing-friendly alternative
protected	LBHttpSolrClient(LBHttpSolrClient.Builder builder)

Method Summary

Modifier and Type	Method and Description
void	close()
protected SolrClient	getClient(String baseUrl)
org.apache.http.client.HttpClient	getHttpClient() Return the HttpClient this instance uses.
protected HttpSolrClient	makeSolrClient(String server)
String	removeSolrServer(String server)
LBHttpSolrClient.Rsp	request(LBHttpSolrClient.Req req) Deprecated. use LBSolrClient.request(LBSolrClient.Req) instead
void	setConnectionTimeout(int timeout) Deprecated. since 7.0 Use LBHttpSolrClient.Builder methods instead.
void	setSoTimeout(int timeout) Deprecated. since 7.0 Use LBHttpSolrClient.Builder methods instead.

Methods inherited from class org.apache.solr.client.solrj.impl.LBSolrClient

addQueryParams, addSolrServer, createServerWrapper, doRequest, getParser, getQueryParams, getRequestWriter, normalize, pickServer, request, request, request, setAliveCheckInterval, setParser, setQueryParams, setRequestWriter, updateAliveList

Methods inherited from class org.apache.solr.client.solrj.SolrClient

add, add, add, add, add, add, add, add, add, add, addBean, addBean, addBean, addBean, addBeans, addBeans, addBeans, addBeans, addBeans, addBeans, commit, commit, commit, commit, commit, commit, deleteById, deleteById, deleteById, deleteById, deleteById, deleteById, deleteById, deleteById, deleteByQuery, deleteByQuery, deleteByQuery, deleteByQuery, getBinder, getById, getById, getById, getById, getById, getById, getById, getById, optimize, optimize, optimize, optimize, optimize, optimize, ping, ping, query, query, query, query, queryAndStreamResponse, queryAndStreamResponse, queryAndStreamResponse, request, rollback, rollback

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LBHttpSolrClient

@Deprecated
protected LBHttpSolrClient(HttpSolrClient.Builder httpSolrClientBuilder,
                                       org.apache.http.client.HttpClient httpClient,
                                       String... solrServerUrl)

Deprecated. use LBHttpSolrClient(Builder) instead, as it is a more extension/subclassing-friendly alternative

The provided httpClient should use a multi-threaded connection manager

LBHttpSolrClient

@Deprecated
protected LBHttpSolrClient(org.apache.http.client.HttpClient httpClient,
                                       ResponseParser parser,
                                       String... solrServerUrl)

Deprecated. use LBHttpSolrClient(Builder) instead, as it is a more extension/subclassing-friendly alternative

The provided httpClient should use a multi-threaded connection manager

LBHttpSolrClient

protected LBHttpSolrClient(LBHttpSolrClient.Builder builder)

Method Detail

makeSolrClient

protected HttpSolrClient makeSolrClient(String server)

setConnectionTimeout

@Deprecated
public void setConnectionTimeout(int timeout)

Deprecated. since 7.0 Use LBHttpSolrClient.Builder methods instead.

setSoTimeout

@Deprecated
public void setSoTimeout(int timeout)

Deprecated. since 7.0 Use LBHttpSolrClient.Builder methods instead.

set soTimeout (read timeout) on the underlying HttpConnectionManager. This is desirable for queries, but probably not for indexing.

request

@Deprecated
public LBHttpSolrClient.Rsp request(LBHttpSolrClient.Req req)
                                         throws SolrServerException,
                                                IOException

Deprecated. use LBSolrClient.request(LBSolrClient.Req) instead

Throws:

SolrServerException

IOException

getClient

protected SolrClient getClient(String baseUrl)

Specified by:

getClient in class LBSolrClient

removeSolrServer

public String removeSolrServer(String server)

Overrides:

removeSolrServer in class LBSolrClient

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Overrides:

close in class LBSolrClient

getHttpClient

public org.apache.http.client.HttpClient getHttpClient()

Return the HttpClient this instance uses.