Package org.apache.solr.client.solrj.impl

Class LBHttp2SolrClient

java.lang.Object

org.apache.solr.client.solrj.SolrClient

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

org.apache.solr.client.solrj.impl.LBHttp2SolrClient

All Implemented Interfaces:

Closeable, Serializable, AutoCloseable

public class LBHttp2SolrClient
extends LBSolrClient

LBHttp2SolrClient or "LoadBalanced LBHttp2SolrClient" is a load balancing wrapper around Http2SolrClient. 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 lbHttp2SolrClient = new LBHttp2SolrClient(http2SolrClient, "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 set up 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 8.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LBHttp2SolrClient.Builder

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

LBSolrClient.Endpoint, LBSolrClient.Req, LBSolrClient.Rsp, LBSolrClient.ServerIterator, LBSolrClient.ServerWrapper

Field Summary

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

aliveCheckIntervalMillis, parser, requestWriter, RETRY_CODES, zombieServers

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

defaultCollection

Constructor Summary

Constructors

Constructor	Description
LBHttp2SolrClient(Http2SolrClient solrClient, String... baseSolrUrls)	Deprecated. Use LBHttp2SolrClient.Builder instead

Method Summary

Modifier and Type	Method	Description
void	addQueryParams(String queryOnlyParam)	Deprecated. you should instead set this on the passed in Http2SolrClient used by the Builder.
Cancellable	asyncReq(LBSolrClient.Req req, AsyncListener<LBSolrClient.Rsp> asyncListener)	Deprecated. Use requestAsync(Req).
protected SolrClient	getClient(String baseUrl)	Deprecated. Use getClient(Endpoint) instead.
protected SolrClient	getClient(LBSolrClient.Endpoint endpoint)
ResponseParser	getParser()
RequestWriter	getRequestWriter()
Set<String>	getUrlParamNames()
CompletableFuture<LBSolrClient.Rsp>	requestAsync(LBSolrClient.Req req)	Execute an asynchronous request against one or more hosts for a given collection.
void	setParser(ResponseParser parser)	Deprecated. Pass in a configured Http2SolrClient instead
void	setQueryParams(Set<String> queryParams)	Deprecated. You should instead set this on the passed in Http2SolrClient used by the Builder.
void	setRequestWriter(RequestWriter writer)	Deprecated. Pass in a configured Http2SolrClient instead

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

addSolrServer, addSolrServer, addZombie, close, createServerWrapper, doRequest, normalize, pickServer, removeSolrEndpoint, removeSolrServer, request, request, request, setAliveCheckInterval, 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, getContext, getDefaultCollection, 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

LBHttp2SolrClient

@Deprecated
public LBHttp2SolrClient(Http2SolrClient solrClient,
                         String... baseSolrUrls)

Deprecated.

Use LBHttp2SolrClient.Builder instead

Method Detail

getClient

@Deprecated
protected SolrClient getClient(String baseUrl)

Deprecated.

Use getClient(Endpoint) instead.

Specified by:

getClient in class LBSolrClient

getClient

protected SolrClient getClient(LBSolrClient.Endpoint endpoint)

Specified by:

getClient in class LBSolrClient

setParser

@Deprecated
public void setParser(ResponseParser parser)

Deprecated.

Pass in a configured Http2SolrClient instead

Note: This setter method is not thread-safe.

Overrides:

setParser in class LBSolrClient

Parameters:

parser - Default Response Parser chosen to parse the response if the parser were not specified as part of the request.

See Also:

SolrRequest.getResponseParser()

getParser

public ResponseParser getParser()

Overrides:

getParser in class LBSolrClient

setRequestWriter

@Deprecated
public void setRequestWriter(RequestWriter writer)

Deprecated.

Pass in a configured Http2SolrClient instead

Choose the RequestWriter to use.

By default, BinaryRequestWriter is used.

Note: This setter method is not thread-safe.

Overrides:

setRequestWriter in class LBSolrClient

Parameters:

writer - Default RequestWriter, used to encode requests sent to the server.

getRequestWriter

public RequestWriter getRequestWriter()

Overrides:

getRequestWriter in class LBSolrClient

getUrlParamNames

public Set<String> getUrlParamNames()

setQueryParams

@Deprecated
public void setQueryParams(Set<String> queryParams)

Deprecated.

You should instead set this on the passed in Http2SolrClient used by the Builder.

addQueryParams

@Deprecated
public void addQueryParams(String queryOnlyParam)

Deprecated.

you should instead set this on the passed in Http2SolrClient used by the Builder.

This method should be removed as being able to add a query parameter isn't compatible with the idea that query params are an immutable property of a solr client.

asyncReq

@Deprecated
public Cancellable asyncReq(LBSolrClient.Req req,
                            AsyncListener<LBSolrClient.Rsp> asyncListener)

Deprecated.

Use requestAsync(Req).

Execute an asynchronous request against a one or more hosts for a given collection.

Parameters:

req - the wrapped request to perform

asyncListener - callers should provide an implementation to handle events: start, success, exception

Returns:

Cancellable allowing the caller to attempt cancellation

requestAsync

public CompletableFuture<LBSolrClient.Rsp> requestAsync(LBSolrClient.Req req)

Execute an asynchronous request against one or more hosts for a given collection. The passed-in Req object includes a List of Endpoints. This method always begins with the first Endpoint in the list and if unsuccessful tries each in turn until the request is successful. Consequently, this method does not actually Load Balance. It is up to the caller to shuffle the List of Endpoints if Load Balancing is desired.

Parameters:

req - the wrapped request to perform

Returns:

a CompletableFuture that tracks the progress of the async request.