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版本:v2.6.x

dumpMessages()

This operation streams WAL messages from a physical channel for data salvage and replication diagnostics. Use it with a checkpoint returned by getReplicateInfo.

Java
public DumpMessagesResp dumpMessages(DumpMessagesReq request)

Request Syntax​

Java
dumpMessages(DumpMessagesReq.builder()
.pchannel(String pchannel)
.startMessageID(GetReplicateInfoResp.MessageID startMessageID)
.startTimetick(Long startTimetick)
.endTimetick(Long endTimetick)
.build());

BUILDER METHODS:

  • pchannel(String pchannel)

    The physical channel to dump messages from.

  • startMessageID(GetReplicateInfoResp.MessageID startMessageID)

    The WAL start position. walName supports RocksMQ, Pulsar, Kafka, and WoodPecker.

  • startTimetick(Long startTimetick)

    The inclusive lower timetick bound. Defaults to 0L.

  • endTimetick(Long endTimetick)

    The upper timetick bound. Defaults to 0L.

RETURN TYPE:

DumpMessagesResp

RETURNS:

A DumpMessagesResp object that iterates over the dumped messages. Each iterated message is a DumpMessageInfo object with the following getters:

  • getMessages() (Iterable<DumpMessageInfo>) -

    The iterable of dumped messages, each of which is a DumpMessageInfo object.

    • getMessageID() (GetReplicateInfoResp.MessageID) -

      The ID of the message.

    • getPayload() (byte[]) -

      The payload of the message.

    • getProperties() (Map<String, String>) -

      The properties of the message.

EXCEPTIONS:

  • MilvusClientException

    This exception will be raised when validation fails or the server returns an error for this operation.

Example​

Java
import io.milvus.v2.client.ConnectConfig;
import io.milvus.v2.client.MilvusClientV2;
import io.milvus.v2.service.cdc.request.DumpMessagesReq;
import io.milvus.v2.service.cdc.request.GetReplicateInfoReq;
import io.milvus.v2.service.cdc.response.DumpMessageInfo;
import io.milvus.v2.service.cdc.response.DumpMessagesResp;
import io.milvus.v2.service.cdc.response.GetReplicateInfoResp;

ConnectConfig connectConfig = ConnectConfig.builder()
.uri("http://localhost:19530")
.token("root:Milvus")
.build();

MilvusClientV2 client = new MilvusClientV2(connectConfig);

GetReplicateInfoResp info = client.getReplicateInfo(GetReplicateInfoReq.builder()
.sourceClusterId("cluster-a")
.targetPchannel("by-dev-rootcoord-dml_0_123v0")
.build());

DumpMessagesResp resp = client.dumpMessages(DumpMessagesReq.builder()
.pchannel("by-dev-rootcoord-dml_0_123v0")
.startMessageID(info.getCheckpoint().getMessageID())
.build());
for (DumpMessageInfo message : resp) {
System.out.println(message.getProperties());
}