[feature](alter backends)backend modify & drop & decommission by ids (#25444)

This commit is contained in:
Guangdong Liu
2023-10-25 14:32:30 +08:00
committed by GitHub
parent 49b73483fd
commit 4f17c2a8b1
17 changed files with 269 additions and 88 deletions

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@ -36,8 +36,16 @@ The node offline operation is used to safely log off the node. The operation is
grammar:
- Find backend through host and port
```sql
ALTER SYSTEM DECOMMISSION BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...];
````
- Find backend through backend_id
```sql
ALTER SYSTEM DECOMMISSION BACKEND "id1","id2"...;
````
illustrate:
@ -55,6 +63,10 @@ ALTER SYSTEM DECOMMISSION BACKEND "host:heartbeat_port"[,"host:heartbeat_port"..
ALTER SYSTEM DECOMMISSION BACKEND "host1:port", "host2:port";
````
```sql
ALTER SYSTEM DECOMMISSION BACKEND "id1", "id2";
````
### Keywords
ALTER, SYSTEM, DECOMMISSION, BACKEND, ALTER SYSTEM

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@ -36,9 +36,16 @@ This statement is used to delete the BACKEND node (administrator only!)
grammar:
- Find backend through host and port
```sql
ALTER SYSTEM DROP BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...]
````
- Find backend through backend_id
```sql
ALTER SYSTEM DROP BACKEND "id1","id2"...;
````
illustrate:
@ -54,6 +61,10 @@ illustrate:
ALTER SYSTEM DROP BACKEND "host1:port", "host2:port";
````
```sql
ALTER SYSTEM DROP BACKEND "ids1", "ids2";
````
### Keywords
ALTER, SYSTEM, DROP, BACKEND, ALTER SYSTEM

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@ -37,8 +37,16 @@ Modify BE node properties (administrator only!)
grammar:
- Find backend through host and port
```sql
ALTER SYSTEM MODIFY BACKEND "host:heartbeat_port" SET ("key" = "value"[, ...]);
````
- Find backend through backend_id
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("key" = "value"[, ...]);
````
illustrate:
@ -62,18 +70,31 @@ Note:
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("tag.location" = "group_a");
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("tag.location" = "group_a", "tag.compute" = "c1");
````
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("tag.location" = "group_a");
ALTER SYSTEM MODIFY BACKEND "id1" SET ("tag.location" = "group_a", "tag.compute" = "c1");
````
2. Modify the query disable property of BE
```sql
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("disable_query" = "true");
````
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("disable_query" = "true");
````
3. Modify the import disable property of BE
```sql
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("disable_load" = "true");
````
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("disable_load" = "true");
````
### Keywords

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@ -36,8 +36,16 @@ ALTER SYSTEM DECOMMISSION BACKEND
语法:
- 通过 host 和 port 查找 backend
```sql
ALTER SYSTEM DECOMMISSION BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...];
```
- 通过 backend_id 查找 backend
```sql
ALTER SYSTEM DECOMMISSION BACKEND "id1","id2"...;
```
说明:
@ -54,6 +62,10 @@ ALTER SYSTEM DECOMMISSION BACKEND "host:heartbeat_port"[,"host:heartbeat_port"..
```sql
ALTER SYSTEM DECOMMISSION BACKEND "host1:port", "host2:port";
```
```sql
ALTER SYSTEM DECOMMISSION BACKEND "id1", "id2";
```
### Keywords

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@ -36,10 +36,18 @@ ALTER SYSTEM DROP BACKEND
语法:
- 通过 host 和 port 查找 backend
```sql
ALTER SYSTEM DROP BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...]
```
- 通过 backend_id 查找 backend
```sql
ALTER SYSTEM DROP BACKEND "id1","id2"...;
```
说明:
1. host 可以是主机名或者ip地址
@ -53,6 +61,10 @@ ALTER SYSTEM DROP BACKEND "host:heartbeat_port"[,"host:heartbeat_port"...]
```sql
ALTER SYSTEM DROP BACKEND "host1:port", "host2:port";
```
```sql
ALTER SYSTEM DROP BACKEND "id1", "id2";
```
### Keywords

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@ -37,10 +37,18 @@ ALTER SYSTEM MKDIFY BACKEND
语法:
- 通过 host 和 port 查找 backend
```sql
ALTER SYSTEM MODIFY BACKEND "host:heartbeat_port" SET ("key" = "value"[, ...]);
```
- 通过 backend_id 查找 backend
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("key" = "value"[, ...]);
````
说明:
1. host 可以是主机名或者ip地址
@ -63,16 +71,31 @@ ALTER SYSTEM MODIFY BACKEND "host:heartbeat_port" SET ("key" = "value"[, ...]);
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("tag.location" = "group_a", "tag.compute" = "c1");
```
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("tag.location" = "group_a");
ALTER SYSTEM MODIFY BACKEND "id1" SET ("tag.location" = "group_a", "tag.compute" = "c1");
````
2. 修改 BE 的查询禁用属性
```sql
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("disable_query" = "true");
```
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("disable_query" = "true");
````
3. 修改 BE 的导入禁用属性
```sql
ALTER SYSTEM MODIFY BACKEND "host1:heartbeat_port" SET ("disable_load" = "true");
```
```sql
ALTER SYSTEM MODIFY BACKEND "id1" SET ("disable_load" = "true");
````
### Keywords
ALTER, SYSTEM, ADD, BACKEND, ALTER SYSTEM

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@ -86,7 +86,7 @@ import com.google.common.collect.Maps;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
@ -739,7 +739,7 @@ public class Alter {
}
public void processAlterCluster(AlterSystemStmt stmt) throws UserException {
clusterHandler.process(Arrays.asList(stmt.getAlterClause()), stmt.getClusterName(), null, null);
clusterHandler.process(Collections.singletonList(stmt.getAlterClause()), stmt.getClusterName(), null, null);
}
private void processRename(Database db, OlapTable table, List<AlterClause> alterClauses) throws DdlException {

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@ -125,7 +125,13 @@ public class SystemHandler extends AlterHandler {
+ "All data on this backend will be discarded permanently. "
+ "If you insist, use DROPP instead of DROP");
}
Env.getCurrentSystemInfo().dropBackends(dropBackendClause.getHostInfos());
if (dropBackendClause.getHostInfos().isEmpty()) {
// drop by id
Env.getCurrentSystemInfo().dropBackendsByIds(dropBackendClause.getIds());
} else {
// drop by host
Env.getCurrentSystemInfo().dropBackends(dropBackendClause.getHostInfos());
}
} else if (alterClause instanceof DecommissionBackendClause) {
// decommission
DecommissionBackendClause decommissionBackendClause = (DecommissionBackendClause) alterClause;
@ -192,6 +198,9 @@ public class SystemHandler extends AlterHandler {
private List<Backend> checkDecommission(DecommissionBackendClause decommissionBackendClause)
throws DdlException {
if (decommissionBackendClause.getHostInfos().isEmpty()) {
return checkDecommissionByIds(decommissionBackendClause.getIds());
}
return checkDecommission(decommissionBackendClause.getHostInfos());
}
@ -226,6 +235,29 @@ public class SystemHandler extends AlterHandler {
return decommissionBackends;
}
public static List<Backend> checkDecommissionByIds(List<String> ids)
throws DdlException {
SystemInfoService infoService = Env.getCurrentSystemInfo();
List<Backend> decommissionBackends = Lists.newArrayList();
// check if exist
for (String id : ids) {
Backend backend = infoService.getBackend(Long.parseLong(id));
if (backend == null) {
throw new DdlException("Backend does not exist, backend id is " + id);
}
if (backend.isDecommissioned()) {
// already under decommission, ignore it
continue;
}
decommissionBackends.add(backend);
}
// TODO(cmy): check if replication num can be met
// TODO(cmy): check remaining space
return decommissionBackends;
}
@Override
public synchronized void cancel(CancelStmt stmt) throws DdlException {
CancelAlterSystemStmt cancelAlterSystemStmt = (CancelAlterSystemStmt) stmt;

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@ -23,12 +23,14 @@ import org.apache.doris.common.util.PropertyAnalyzer;
import org.apache.doris.resource.Tag;
import com.google.common.collect.Maps;
import lombok.Getter;
import java.util.List;
import java.util.Map;
public class AddBackendClause extends BackendClause {
protected Map<String, String> properties = Maps.newHashMap();
@Getter
private Map<String, String> tagMap;
public AddBackendClause(List<String> hostPorts) {
@ -43,10 +45,6 @@ public class AddBackendClause extends BackendClause {
}
}
public Map<String, String> getTagMap() {
return tagMap;
}
@Override
public void analyze(Analyzer analyzer) throws AnalysisException {
super.analyze(analyzer);
@ -69,9 +67,9 @@ public class AddBackendClause extends BackendClause {
StringBuilder sb = new StringBuilder();
sb.append("ADD ");
sb.append("BACKEND ");
for (int i = 0; i < hostPorts.size(); i++) {
sb.append("\"").append(hostPorts.get(i)).append("\"");
if (i != hostPorts.size() - 1) {
for (int i = 0; i < params.size(); i++) {
sb.append("\"").append(params.get(i)).append("\"");
if (i != params.size() - 1) {
sb.append(", ");
}
}

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@ -25,19 +25,17 @@ import org.apache.doris.mysql.privilege.PrivPredicate;
import org.apache.doris.qe.ConnectContext;
import com.google.common.base.Preconditions;
import lombok.Getter;
@Getter
public class AlterSystemStmt extends DdlStmt {
private AlterClause alterClause;
private final AlterClause alterClause;
public AlterSystemStmt(AlterClause alterClause) {
this.alterClause = alterClause;
}
public AlterClause getAlterClause() {
return alterClause;
}
@Override
public void analyze(Analyzer analyzer) throws UserException {
@ -65,9 +63,7 @@ public class AlterSystemStmt extends DdlStmt {
@Override
public String toSql() {
StringBuilder sb = new StringBuilder();
sb.append("ALTER SYSTEM ").append(alterClause.toSql());
return sb.toString();
return "ALTER SYSTEM " + alterClause.toSql();
}
@Override

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@ -24,37 +24,46 @@ import org.apache.doris.system.SystemInfoService.HostInfo;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import lombok.Getter;
import org.apache.commons.lang3.NotImplementedException;
import java.util.List;
import java.util.Map;
public class BackendClause extends AlterClause {
protected List<String> hostPorts;
protected List<String> params;
@Getter
protected List<HostInfo> hostInfos;
@Getter
protected List<String> ids;
public static final String MUTLI_TAG_DISABLED_MSG = "Not support multi tags for Backend now. "
+ "You can set 'enable_multi_tags=true' in fe.conf to enable this feature.";
public static final String NEED_LOCATION_TAG_MSG
= "Backend must have location type tag. Eg: 'tag.location' = 'xxx'.";
protected BackendClause(List<String> hostPorts) {
protected BackendClause(List<String> params) {
super(AlterOpType.ALTER_OTHER);
this.hostPorts = hostPorts;
this.params = params;
this.ids = Lists.newArrayList();
this.hostInfos = Lists.newArrayList();
}
public List<HostInfo> getHostInfos() {
return hostInfos;
}
@Override
public void analyze(Analyzer analyzer) throws AnalysisException {
for (String hostPort : hostPorts) {
HostInfo hostInfo = SystemInfoService.getHostAndPort(hostPort);
hostInfos.add(hostInfo);
for (String param : params) {
if (!param.contains(":")) {
ids.add(param);
} else {
HostInfo hostInfo = SystemInfoService.getHostAndPort(param);
this.hostInfos.add(hostInfo);
}
}
Preconditions.checkState(!hostInfos.isEmpty());
Preconditions.checkState(!this.hostInfos.isEmpty() || !this.ids.isEmpty(),
"hostInfos or ids can not be empty");
}
@Override

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@ -29,9 +29,9 @@ public class DecommissionBackendClause extends BackendClause {
public String toSql() {
StringBuilder sb = new StringBuilder();
sb.append("DECOMMISSION BACKEND ");
for (int i = 0; i < hostPorts.size(); i++) {
sb.append("\"").append(hostPorts.get(i)).append("\"");
if (i != hostPorts.size() - 1) {
for (int i = 0; i < params.size(); i++) {
sb.append("\"").append(params.get(i)).append("\"");
if (i != params.size() - 1) {
sb.append(", ");
}
}

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@ -17,52 +17,31 @@
package org.apache.doris.analysis;
import org.apache.doris.common.AnalysisException;
import org.apache.doris.common.Config;
import org.apache.doris.system.SystemInfoService;
import org.apache.doris.system.SystemInfoService.HostInfo;
import com.google.common.base.Preconditions;
import lombok.Getter;
import java.util.List;
@Getter
public class DropBackendClause extends BackendClause {
private boolean force;
private final boolean force;
public DropBackendClause(List<String> hostPorts) {
super(hostPorts);
public DropBackendClause(List<String> params) {
super(params);
this.force = true;
}
public DropBackendClause(List<String> hostPorts, boolean force) {
super(hostPorts);
public DropBackendClause(List<String> params, boolean force) {
super(params);
this.force = force;
}
public boolean isForce() {
return force;
}
@Override
public void analyze(Analyzer analyzer) throws AnalysisException {
if (Config.enable_fqdn_mode) {
for (String hostPort : hostPorts) {
HostInfo hostInfo = SystemInfoService.getHostAndPort(hostPort);
hostInfos.add(hostInfo);
}
Preconditions.checkState(!hostInfos.isEmpty());
} else {
super.analyze(analyzer);
}
}
@Override
public String toSql() {
StringBuilder sb = new StringBuilder();
sb.append("DROP BACKEND ");
for (int i = 0; i < hostPorts.size(); i++) {
sb.append("\"").append(hostPorts.get(i)).append("\"");
if (i != hostPorts.size() - 1) {
for (int i = 0; i < params.size(); i++) {
sb.append("\"").append(params.get(i)).append("\"");
if (i != params.size() - 1) {
sb.append(", ");
}
}

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@ -23,14 +23,16 @@ import org.apache.doris.common.util.PropertyAnalyzer;
import org.apache.doris.resource.Tag;
import com.google.common.collect.Maps;
import lombok.Getter;
import org.apache.commons.lang3.StringUtils;
import java.util.List;
import java.util.Map;
public class ModifyBackendClause extends BackendClause {
protected Map<String, String> properties = Maps.newHashMap();
protected Map<String, String> properties;
protected Map<String, String> analyzedProperties = Maps.newHashMap();
@Getter
private Map<String, String> tagMap = null;
private Boolean isQueryDisabled = null;
private Boolean isLoadDisabled = null;
@ -74,10 +76,6 @@ public class ModifyBackendClause extends BackendClause {
}
}
public Map<String, String> getTagMap() {
return tagMap;
}
public Boolean isQueryDisabled() {
return isQueryDisabled;
}
@ -90,9 +88,9 @@ public class ModifyBackendClause extends BackendClause {
public String toSql() {
StringBuilder sb = new StringBuilder();
sb.append("MODIFY BACKEND ");
for (int i = 0; i < hostPorts.size(); i++) {
sb.append("\"").append(hostPorts.get(i)).append("\"");
if (i != hostPorts.size() - 1) {
for (int i = 0; i < params.size(); i++) {
sb.append("\"").append(params.get(i)).append("\"");
if (i != params.size() - 1) {
sb.append(", ");
}
}

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@ -235,12 +235,21 @@ public class SystemInfoService {
.getHostPortInAccessibleFormat(hostInfo.getHost(), hostInfo.getPort());
throw new DdlException("backend does not exists[" + backendIdentifier + "]");
}
}
for (HostInfo hostInfo : hostInfos) {
dropBackend(hostInfo.getHost(), hostInfo.getPort());
}
}
public void dropBackendsByIds(List<String> ids) throws DdlException {
for (String id : ids) {
if (getBackend(Long.parseLong(id)) == null) {
throw new DdlException("backend does not exists[" + id + "]");
}
dropBackend(Long.parseLong(id));
}
}
// for decommission
public void dropBackend(long backendId) throws DdlException {
Backend backend = getBackend(backendId);
@ -896,14 +905,26 @@ public class SystemInfoService {
public void modifyBackends(ModifyBackendClause alterClause) throws UserException {
List<HostInfo> hostInfos = alterClause.getHostInfos();
List<Backend> backends = Lists.newArrayList();
for (HostInfo hostInfo : hostInfos) {
Backend be = getBackendWithHeartbeatPort(hostInfo.getHost(), hostInfo.getPort());
if (be == null) {
throw new DdlException(
"backend does not exists[" + NetUtils
.getHostPortInAccessibleFormat(hostInfo.getHost(), hostInfo.getPort()) + "]");
if (hostInfos.isEmpty()) {
List<String> ids = alterClause.getIds();
for (String id : ids) {
long backendId = Long.parseLong(id);
Backend be = getBackend(backendId);
if (be == null) {
throw new DdlException("backend does not exists[" + backendId + "]");
}
backends.add(be);
}
} else {
for (HostInfo hostInfo : hostInfos) {
Backend be = getBackendWithHeartbeatPort(hostInfo.getHost(), hostInfo.getPort());
if (be == null) {
throw new DdlException(
"backend does not exists[" + NetUtils
.getHostPortInAccessibleFormat(hostInfo.getHost(), hostInfo.getPort()) + "]");
}
backends.add(be);
}
backends.add(be);
}
for (Backend be : backends) {

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@ -35,7 +35,7 @@ import java.util.List;
public class DecommissionBackendTest extends TestWithFeService {
@Override
protected int backendNum() {
return 3;
return 4;
}
@Override
@ -78,18 +78,18 @@ public class DecommissionBackendTest extends TestWithFeService {
// 5. execute decommission
Backend srcBackend = null;
for (Backend backend : idToBackendRef.values()) {
if (Env.getCurrentInvertedIndex().getTabletIdsByBackendId(backend.getId()).size() > 0) {
if (!Env.getCurrentInvertedIndex().getTabletIdsByBackendId(backend.getId()).isEmpty()) {
srcBackend = backend;
break;
}
}
Assertions.assertTrue(srcBackend != null);
Assertions.assertNotNull(srcBackend);
String decommissionStmtStr = "alter system decommission backend \"127.0.0.1:" + srcBackend.getHeartbeatPort() + "\"";
AlterSystemStmt decommissionStmt = (AlterSystemStmt) parseAndAnalyzeStmt(decommissionStmtStr);
Env.getCurrentEnv().getAlterInstance().processAlterCluster(decommissionStmt);
Assertions.assertEquals(true, srcBackend.isDecommissioned());
Assertions.assertTrue(srcBackend.isDecommissioned());
long startTimestamp = System.currentTimeMillis();
while (System.currentTimeMillis() - startTimestamp < 90000
&& Env.getCurrentSystemInfo().getIdToBackend().containsKey(srcBackend.getId())) {
@ -110,6 +110,34 @@ public class DecommissionBackendTest extends TestWithFeService {
}
@Test
public void testDecommissionBackendById() throws Exception {
ImmutableMap<Long, Backend> idToBackendRef = Env.getCurrentSystemInfo().getIdToBackend();
Backend srcBackend = idToBackendRef.values().asList().get(0);
Assertions.assertNotNull(srcBackend);
// decommission backend by id
String decommissionByIdStmtStr = "alter system decommission backend \"" + srcBackend.getId() + "\"";
AlterSystemStmt decommissionByIdStmt = (AlterSystemStmt) parseAndAnalyzeStmt(decommissionByIdStmtStr);
Env.getCurrentEnv().getAlterInstance().processAlterCluster(decommissionByIdStmt);
Assertions.assertTrue(srcBackend.isDecommissioned());
long startTimestamp = System.currentTimeMillis();
while (System.currentTimeMillis() - startTimestamp < 90000
&& Env.getCurrentSystemInfo().getIdToBackend().containsKey(srcBackend.getId())) {
Thread.sleep(1000);
}
Assertions.assertEquals(backendNum() - 1, Env.getCurrentSystemInfo().getIdToBackend().size());
// add backend
String addBackendStmtStr = "alter system add backend \"127.0.0.1:" + srcBackend.getHeartbeatPort() + "\"";
AlterSystemStmt addBackendStmt = (AlterSystemStmt) parseAndAnalyzeStmt(addBackendStmtStr);
Env.getCurrentEnv().getAlterInstance().processAlterCluster(addBackendStmt);
Assertions.assertEquals(backendNum(), Env.getCurrentSystemInfo().getIdToBackend().size());
}
@Test
public void testDecommissionBackendWithDropTable() throws Exception {
// 1. create connect context
@ -132,12 +160,12 @@ public class DecommissionBackendTest extends TestWithFeService {
Backend srcBackend = null;
for (Backend backend : idToBackendRef.values()) {
if (Env.getCurrentInvertedIndex().getTabletIdsByBackendId(backend.getId()).size() > 0) {
if (!Env.getCurrentInvertedIndex().getTabletIdsByBackendId(backend.getId()).isEmpty()) {
srcBackend = backend;
break;
}
}
Assertions.assertTrue(srcBackend != null);
Assertions.assertNotNull(srcBackend);
// 5. drop table tbl1
dropTable("db2.tbl1", false);
@ -146,7 +174,7 @@ public class DecommissionBackendTest extends TestWithFeService {
String decommissionStmtStr = "alter system decommission backend \"127.0.0.1:" + srcBackend.getHeartbeatPort() + "\"";
AlterSystemStmt decommissionStmt = (AlterSystemStmt) parseAndAnalyzeStmt(decommissionStmtStr);
Env.getCurrentEnv().getAlterInstance().processAlterCluster(decommissionStmt);
Assertions.assertEquals(true, srcBackend.isDecommissioned());
Assertions.assertTrue(srcBackend.isDecommissioned());
long startTimestamp = System.currentTimeMillis();
while (System.currentTimeMillis() - startTimestamp < 90000
@ -163,7 +191,7 @@ public class DecommissionBackendTest extends TestWithFeService {
// TabletInvertedIndex still holds these tablets of srcBackend, but they are all in recycled status
List<Long> tabletList = Env.getCurrentInvertedIndex().getTabletIdsByBackendId(srcBackend.getId());
Assertions.assertTrue(tabletList.size() > 0);
Assertions.assertFalse(tabletList.isEmpty());
Assertions.assertTrue(Env.getCurrentRecycleBin().allTabletsInRecycledStatus(tabletList));
// recover tbl1, because tbl1 has more than one replica, so it still can be recovered
@ -176,4 +204,6 @@ public class DecommissionBackendTest extends TestWithFeService {
Assertions.assertEquals(backendNum(), Env.getCurrentSystemInfo().getIdToBackend().size());
}
}

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@ -264,6 +264,33 @@ public class SystemInfoServiceTest {
}
}
@Test
public void removeBackendTestByBackendId() throws UserException {
clearAllBackend();
AddBackendClause stmt = new AddBackendClause(Lists.newArrayList("192.168.0.1:1234"));
stmt.analyze(analyzer);
try {
Env.getCurrentSystemInfo().addBackends(stmt.getHostInfos(), true);
} catch (DdlException e) {
e.printStackTrace();
}
DropBackendClause dropStmt = new DropBackendClause(Lists.newArrayList(String.valueOf(backendId)));
dropStmt.analyze(analyzer);
try {
Env.getCurrentSystemInfo().dropBackends(dropStmt.getHostInfos());
} catch (DdlException e) {
e.printStackTrace();
Assert.fail();
}
try {
Env.getCurrentSystemInfo().dropBackends(dropStmt.getHostInfos());
} catch (DdlException e) {
Assert.assertTrue(e.getMessage().contains("does not exist"));
}
}
@Test
public void testSaveLoadBackend() throws Exception {
clearAllBackend();