Package org.apache.druid.server.http

Class SegmentListerResource

java.lang.Object

org.apache.druid.server.http.SegmentListerResource

public class SegmentListerResource
extends Object

Endpoints exposed here are to be used only for druid internal management of segments by Coordinators, Brokers etc.

Field Summary

Fields

Modifier and Type	Field	Description
protected com.fasterxml.jackson.databind.ObjectMapper	jsonMapper
protected static org.apache.druid.java.util.emitter.EmittingLogger	log
protected com.fasterxml.jackson.databind.ObjectMapper	smileMapper

Constructor Summary

Constructors

Constructor	Description
SegmentListerResource(com.fasterxml.jackson.databind.ObjectMapper jsonMapper, com.fasterxml.jackson.databind.ObjectMapper smileMapper, BatchDataSegmentAnnouncer announcer, SegmentLoadDropHandler loadDropRequestHandler)

Method Summary

Modifier and Type	Method	Description
void	applyDataSegmentChangeRequests(long timeout, List<DataSegmentChangeRequest> changeRequestList, javax.servlet.http.HttpServletRequest req)	This endpoint is used by HttpLoadQueuePeon to assign segment load/drop requests batch.
Void	getSegments(long counter, long hash, long timeout, javax.servlet.http.HttpServletRequest req)	This endpoint is used by HttpServerInventoryView to keep an up-to-date list of segments served by historical/realtime nodes.

Methods inherited from class java.lang.Object

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

Field Detail

log

protected static final org.apache.druid.java.util.emitter.EmittingLogger log

jsonMapper

protected final com.fasterxml.jackson.databind.ObjectMapper jsonMapper

smileMapper

protected final com.fasterxml.jackson.databind.ObjectMapper smileMapper

Constructor Detail

SegmentListerResource

@Inject
public SegmentListerResource(com.fasterxml.jackson.databind.ObjectMapper jsonMapper,
                             com.fasterxml.jackson.databind.ObjectMapper smileMapper,
                             @Nullable
                             BatchDataSegmentAnnouncer announcer,
                             @Nullable
                             SegmentLoadDropHandler loadDropRequestHandler)

Method Detail

getSegments

public Void getSegments(long counter,
                        long hash,
                        long timeout,
                        @Context
                        javax.servlet.http.HttpServletRequest req)
                 throws IOException

This endpoint is used by HttpServerInventoryView to keep an up-to-date list of segments served by historical/realtime nodes. This endpoint lists segments served by this server and can also incrementally provide the segments added/dropped since last response. Here is how, this is used. (1) Client sends first request /druid/internal/v1/segments?counter=-1&timeout= Server responds with list of segments currently served and a pair. (2) Client sends subsequent requests /druid/internal/v1/segments?counter=&hash=&timeout= Where values are used from the last response. Server responds with list of segment updates since given counter. This endpoint makes the client wait till either there is some segment update or given timeout elapses. So, clients keep on sending next request immediately after receiving the response in order to keep the list of segments served by this server up-to-date.

Parameters:

counter - counter received in last response.

hash - hash received in last response.

timeout - after which response is sent even if there are no new segment updates.

req -

Returns:

null to avoid "MUST return a non-void type" warning.

Throws:

IOException

applyDataSegmentChangeRequests

public void applyDataSegmentChangeRequests(long timeout,
                                           List<DataSegmentChangeRequest> changeRequestList,
                                           @Context
                                           javax.servlet.http.HttpServletRequest req)
                                    throws IOException

This endpoint is used by HttpLoadQueuePeon to assign segment load/drop requests batch. This endpoint makes the client wait till one of the following events occur. Note that this is implemented using async IO so no jetty threads are held while in wait. (1) Given timeout elapses. (2) Some load/drop request completed. It returns a map of "load/drop request -> SUCCESS/FAILED/PENDING status" for each request in the batch.

Throws:

IOException