日志服务使用Shard控制Logstore或MetricStore读写数据的能力，数据必定保存在某一个Shard中。本文通过代码示例介绍如何查询、分裂、合并Shard。
前提条件
已开通日志服务。更多信息，请参见开通日志服务。
已创建RAM用户并完成授权。具体操作，请参见创建RAM用户并完成授权。
已配置环境变量ALIBABA_CLOUD_ACCESS_KEY_ID和ALIBABA_CLOUD_ACCESS_KEY_SECRET。具体操作，请参见在Linux、macOS和Windows系统配置环境变量。
重要阿里云账号的AccessKey拥有所有API的访问权限，建议您使用RAM用户的AccessKey进行API访问或日常运维。
强烈建议不要把AccessKey ID和AccessKey Secret保存到工程代码里，否则可能导致AccessKey泄露，威胁您账号下所有资源的安全。
已安装日志服务Java SDK。具体操作，请参见安装Java SDK。
已创建Project、标准型Logstore。具体操作，请参见创建项目Project、创建Logstore。
分裂Shard、合并Shard需要该Shard状态为readwrite,Shard状态为readonly分裂或者合并会报错。
注意事项
本示例以华东1（杭州）的公网Endpoint为例，其公网Endpoint为https://cn-hangzhou.log.aliyuncs.com。如果您通过与Project同地域的其他阿里云产品访问日志服务，请使用内网Endpointhttps://cn-hangzhou-intranet.log.aliyuncs.com。关于日志服务支持的地域与Endpoint的对应关系，请参见服务入口。
查询Shard示例代码
以下代码用于查询指定Logstore的Shard信息。
import com.aliyun.openservices.log.Client;
import com.aliyun.openservices.log.common.Shard;
import com.aliyun.openservices.log.exception.LogException;
import com.aliyun.openservices.log.response.ListShardResponse;
public class ListShards {
public static void main(String[] args) throws LogException {
// 本示例从环境变量中获取AccessKey ID和AccessKey Secret。
String accessId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
String accessKey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
// 输入Project名称。
String projectName = "ali-test-project";
// 输入Logstore名称。
String logstoreName = "ali-test-logstore";
// 设置日志服务的服务接入点。此处以杭州为例，其它地域请根据实际情况填写。
String host = "https://cn-hangzhou.log.aliyuncs.com";
// 创建日志服务Client。
Client client = new Client(host, accessId, accessKey);
try {
System.out.println("ready to list shards");
// 查询指定Logstore的所有Shard。
ListShardResponse response = client.ListShard(projectName, logstoreName);
for(Shard shard : response.GetShards()){
System.out.println("Shard ID is :" + shard.getShardId());
System.out.println("Shard status is :" + shard.getStatus());
System.out.println("Shard begin key is :" + shard.getInclusiveBeginKey());
System.out.println("Shard end key is :" + shard.getExclusiveEndKey());
System.out.println("Shard create time is :" + shard.getCreateTime());
}
System.out.println(String.format("list shards of %s success", logstoreName));
} catch (LogException e) {
System.out.println("LogException e :" + e.toString());
System.out.println("error code :" + e.GetErrorCode());
System.out.println("error message :" + e.GetErrorMessage());
throw e;
}
}
}预期结果如下：
ready to list shards
Shard ID is :0
Shard status is :readwrite
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard create time is :1667810747
Shard ID is :1
Shard status is :readwrite
Shard begin key is :7f000000000000000000000000000000
Shard end key is :ffffffffffffffffffffffffffffffff
Shard create time is :1667810747
list shards of ali-test-logstore success分裂Shard示例代码
以下代码用于分裂指定Logstore的Shard。
import com.aliyun.openservices.log.Client;
import com.aliyun.openservices.log.common.Shard;
import com.aliyun.openservices.log.exception.LogException;
import com.aliyun.openservices.log.response.ListShardResponse;
import java.util.concurrent.TimeUnit;
public class SplitShard {
public static void main(String[] args) throws LogException {
// 本示例从环境变量中获取AccessKey ID和AccessKey Secret。
String accessId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
String accessKey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
// 输入Project名称。
String projectName = "ali-test-project";
// 输入Logstore名称。
String logstoreName = "ali-test-logstore";
// 设置日志服务的服务接入点。此处以杭州为例，其它地域请根据实际情况填写。
String host = "https://cn-hangzhou.log.aliyuncs.com";
// 创建日志服务Client。
Client client = new Client(host, accessId, accessKey);
try {
System.out.println("ready to list shard");
// 分裂之前先查看所有Shard。
ListShardResponse response = client.ListShard(projectName, logstoreName);
for(Shard shard : response.GetShards()){
System.out.println("Shard ID is :" + shard.getShardId());
System.out.println("Shard status is :" + shard.getStatus());
System.out.println("Shard begin key is :" + shard.getInclusiveBeginKey());
System.out.println("Shard end key is :" + shard.getExclusiveEndKey());
}
System.out.println("ready to split shard");
// 分裂Shard 0。
client.SplitShard(projectName, logstoreName, 0, "3f000000000000000000000000000000");
// 等待60秒后再查询Shard。
TimeUnit.SECONDS.sleep(60);
System.out.println(String.format("split shards of %s success", logstoreName));
// 分裂之后再查看所有Shard。
ListShardResponse response1 = client.ListShard(projectName, logstoreName);
for(Shard shard1 : response1.GetShards()){
System.out.println("Shard ID is :" + shard1.getShardId());
System.out.println("Shard status is :" + shard1.getStatus());
System.out.println("Shard begin key is :" + shard1.getInclusiveBeginKey());
System.out.println("Shard end key is :" + shard1.getExclusiveEndKey());
}
} catch (LogException e) {
System.out.println("LogException e :" + e.toString());
System.out.println("error code :" + e.GetErrorCode());
System.out.println("error message :" + e.GetErrorMessage());
throw e;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}预期结果如下：
ready to list shard
Shard ID is :0
Shard status is :readwrite
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard ID is :1
Shard status is :readwrite
Shard begin key is :7f000000000000000000000000000000
Shard end key is :ffffffffffffffffffffffffffffffff
ready to split shard
split shards of ali-test-logstore success
Shard ID is :2
Shard status is :readwrite
Shard begin key is :00000000000000000000000000000000
Shard end key is :3f000000000000000000000000000000
Shard ID is :3
Shard status is :readwrite
Shard begin key is :3f000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard ID is :1
Shard status is :readwrite
Shard begin key is :7f000000000000000000000000000000
Shard end key is :ffffffffffffffffffffffffffffffff
Shard ID is :0
Shard status is :readonly
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000合并Shard示例代码
以下代码用于合并指定Logstore的Shard。
import com.aliyun.openservices.log.Client;
import com.aliyun.openservices.log.common.Shard;
import com.aliyun.openservices.log.exception.LogException;
import com.aliyun.openservices.log.response.ListShardResponse;
import java.util.concurrent.TimeUnit;
public class MergeShard {
public static void main(String[] args) throws LogException {
// 本示例从环境变量中获取AccessKey ID和AccessKey Secret。
String accessId = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_ID");
String accessKey = System.getenv("ALIBABA_CLOUD_ACCESS_KEY_SECRET");
// 输入Project名称。
String projectName = "ali-test-project";
// 输入Logstore名称。
String logstoreName = "ali-test-logstore";
// 设置日志服务的服务接入点。此处以杭州为例，其它地域请根据实际情况填写。
String host = "https://cn-hangzhou.log.aliyuncs.com";
// 创建日志服务Client。
Client client = new Client(host, accessId, accessKey);
try {
System.out.println("ready to list shard");
// 合并之前先查看所有Shard。
ListShardResponse response = client.ListShard(projectName, logstoreName);
for(Shard shard : response.GetShards()){
System.out.println("Shard ID is :" + shard.getShardId());
System.out.println("Shard status is :" + shard.getStatus());
System.out.println("Shard begin key is :" + shard.getInclusiveBeginKey());
System.out.println("Shard end key is :" + shard.getExclusiveEndKey());
}
System.out.println("ready to merge shard");
// 将Shard 2和3进行合并。服务端会自动找到相邻的下一个Shard进行合并。
client.MergeShards(projectName, logstoreName, 2);
// 等待60秒后再查询Shard。
TimeUnit.SECONDS.sleep(60);
System.out.println(String.format("merge shards of %s success", logstoreName));
// 合并之后再查看所有Shard。
ListShardResponse response1 = client.ListShard(projectName, logstoreName);
for(Shard shard1 : response1.GetShards()){
System.out.println("Shard ID is :" + shard1.getShardId());
System.out.println("Shard status is :" + shard1.getStatus());
System.out.println("Shard begin key is :" + shard1.getInclusiveBeginKey());
System.out.println("Shard end key is :" + shard1.getExclusiveEndKey());
}
} catch (LogException e) {
System.out.println("LogException e :" + e.toString());
System.out.println("error code :" + e.GetErrorCode());
System.out.println("error message :" + e.GetErrorMessage());
throw e;
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}预期结果如下：
ready to list shard
Shard ID is :2
Shard status is :readwrite
Shard begin key is :00000000000000000000000000000000
Shard end key is :3f000000000000000000000000000000
Shard ID is :3
Shard status is :readwrite
Shard begin key is :3f000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard ID is :1
Shard status is :readwrite
Shard begin key is :7f000000000000000000000000000000
Shard end key is :ffffffffffffffffffffffffffffffff
Shard ID is :0
Shard status is :readonly
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
ready to merge shard
merge shards of ali-test-logstore success
Shard ID is :4
Shard status is :readwrite
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard ID is :1
Shard status is :readwrite
Shard begin key is :7f000000000000000000000000000000
Shard end key is :ffffffffffffffffffffffffffffffff
Shard ID is :0
Shard status is :readonly
Shard begin key is :00000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000
Shard ID is :2
Shard status is :readonly
Shard begin key is :00000000000000000000000000000000
Shard end key is :3f000000000000000000000000000000
Shard ID is :3
Shard status is :readonly
Shard begin key is :3f000000000000000000000000000000
Shard end key is :7f000000000000000000000000000000相关文档
在调用API接口过程中，若服务端返回结果中包含错误信息，则表示调用API接口失败。您可以参考API错误码对照表查找对应的解决方法。更多信息，请参见API错误处理对照表。
阿里云OpenAPI开发者门户提供调试、SDK、示例和配套文档。通过OpenAPI，您无需手动封装请求和签名操作，就可以快速对日志服务API进行调试。更多信息，请参见OpenAPI开发者门户。
为满足越来越多的自动化日志服务配置需求，日志服务提供命令行工具CLI（Command Line Interface）。更多信息，请参见日志服务命令行工具CLI。
关于Shard API接口说明，请参见如下：
更多示例代码，请参见Aliyun Log Java SDK on GitHub。
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