[Feature](show) show backend config using ShowStmt

fe/fe-core/src/main/antlr4/org/apache/doris/nereids/DorisParser.g4

@@ -40,6 +40,7 @@ statement
     | DROP (PROCEDURE | PROC) (IF EXISTS)? name=multipartIdentifier #dropProcedure
     | SHOW PROCEDURE STATUS (LIKE pattern=valueExpression | whereClause)? #showProcedureStatus
     | SHOW CREATE PROCEDURE name=multipartIdentifier #showCreateProcedure
+    | ADMIN? SHOW type=(FRONTEND | BACKEND) CONFIG (LIKE pattern=valueExpression)? (FROM backendId=INTEGER_VALUE)? #showConfig
     ;
 
 statementBase

fe/fe-core/src/main/antlr4/org/apache/doris/nereids/PLParser.g4

@@ -101,6 +101,7 @@ stmt :
      | drop_procedure_stmt
      | show_procedure_stmt
      | show_create_procedure_stmt
+     | show_config_stmt
      | exec_stmt
      | exit_stmt
      | fetch_stmt
@@ -343,6 +344,10 @@ show_create_procedure_stmt:
       SHOW CREATE PROCEDURE name=multipartIdentifier
     ;      
 
+show_config_stmt:
+      SHOW type=(FRONTEND | BACKEND) CONFIG (LIKE pattern=valueExpression)? (FROM backendId=INTEGER_VALUE)?
+    ;
+
 create_routine_params :
        LEFT_PAREN RIGHT_PAREN
      | LEFT_PAREN create_routine_param_item (COMMA create_routine_param_item)* RIGHT_PAREN

fe/fe-core/src/main/cup/sql_parser.cup

@@ -60,6 +60,7 @@ import org.apache.doris.load.loadv2.LoadTask;
 import org.apache.doris.policy.PolicyTypeEnum;
 import org.apache.doris.resource.workloadschedpolicy.WorkloadConditionMeta;
 import org.apache.doris.resource.workloadschedpolicy.WorkloadActionMeta;
+import org.apache.doris.system.NodeType;
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
@@ -4711,7 +4712,15 @@ show_param ::=
     :}
     | KW_FRONTEND KW_CONFIG opt_wild_where
     {:
-        RESULT = new ShowConfigStmt(AdminSetConfigStmt.ConfigType.FRONTEND, parser.wild);
+        RESULT = new ShowConfigStmt(NodeType.FRONTEND, parser.wild);
+    :}
+    | KW_BACKEND KW_CONFIG opt_wild_where
+    {:
+        RESULT = new ShowConfigStmt(NodeType.BACKEND, parser.wild);
+    :}
+    | KW_BACKEND KW_CONFIG opt_wild_where KW_FROM INTEGER_LITERAL:backendId
+    {:
+        RESULT = new ShowConfigStmt(NodeType.BACKEND, parser.wild, backendId);
     :}
     | KW_TABLET KW_STORAGE KW_FORMAT
     {:
@@ -7850,20 +7859,28 @@ admin_stmt ::=
     :}
     | KW_ADMIN KW_SET KW_FRONTEND KW_CONFIG opt_key_value_map:configs
     {:
-        RESULT = new AdminSetConfigStmt(AdminSetConfigStmt.ConfigType.FRONTEND, configs, false);
+        RESULT = new AdminSetConfigStmt(NodeType.FRONTEND, configs, false);
     :}
     | KW_ADMIN KW_SET KW_ALL KW_FRONTENDS KW_CONFIG opt_key_value_map:configs
     {:
-        RESULT = new AdminSetConfigStmt(AdminSetConfigStmt.ConfigType.FRONTEND, configs, true);
+        RESULT = new AdminSetConfigStmt(NodeType.FRONTEND, configs, true);
     :}
     | KW_ADMIN KW_SET KW_FRONTEND KW_CONFIG opt_key_value_map:configs KW_ALL
     {:
-        RESULT = new AdminSetConfigStmt(AdminSetConfigStmt.ConfigType.FRONTEND, configs, true);
+        RESULT = new AdminSetConfigStmt(NodeType.FRONTEND, configs, true);
     :}
     // deprecated
     | KW_ADMIN KW_SHOW KW_FRONTEND KW_CONFIG opt_wild_where
     {:
-        RESULT = new ShowConfigStmt(AdminSetConfigStmt.ConfigType.FRONTEND, parser.wild);
+        RESULT = new ShowConfigStmt(NodeType.FRONTEND, parser.wild);
+    :}
+    | KW_ADMIN KW_SHOW KW_BACKEND KW_CONFIG opt_wild_where
+    {:
+        RESULT = new ShowConfigStmt(NodeType.BACKEND, parser.wild);
+    :}
+    | KW_ADMIN KW_SHOW KW_BACKEND KW_CONFIG opt_wild_where KW_FROM INTEGER_LITERAL:backendId
+    {:
+        RESULT = new ShowConfigStmt(NodeType.BACKEND, parser.wild, backendId);
     :}
     | KW_ADMIN KW_CHECK KW_TABLET LPAREN integer_list:tabletIds RPAREN opt_properties:properties
     {:

fe/fe-core/src/main/java/org/apache/doris/analysis/AdminSetConfigStmt.java

@@ -26,6 +26,7 @@
 import org.apache.doris.mysql.privilege.PrivPredicate;
 import org.apache.doris.qe.ConnectContext;
 import org.apache.doris.qe.OriginStatement;
+import org.apache.doris.system.NodeType;
 
 import com.google.common.collect.Maps;
 
@@ -34,18 +35,13 @@
 // admin set frontend config ("key" = "value");
 public class AdminSetConfigStmt extends DdlStmt {
 
-    public enum ConfigType {
-        FRONTEND,
-        BACKEND
-    }
-
     private boolean applyToAll;
-    private ConfigType type;
+    private NodeType type;
     private Map<String, String> configs;
 
     private RedirectStatus redirectStatus = RedirectStatus.NO_FORWARD;
 
-    public AdminSetConfigStmt(ConfigType type, Map<String, String> configs, boolean applyToAll) {
+    public AdminSetConfigStmt(NodeType type, Map<String, String> configs, boolean applyToAll) {
         this.type = type;
         this.configs = configs;
         if (this.configs == null) {
@@ -62,7 +58,7 @@ public AdminSetConfigStmt(ConfigType type, Map<String, String> configs, boolean
         }
     }
 
-    public ConfigType getType() {
+    public NodeType getType() {
         return type;
     }
 
@@ -86,7 +82,7 @@ public void analyze(Analyzer analyzer) throws AnalysisException, UserException {
             ErrorReport.reportAnalysisException(ErrorCode.ERR_SPECIFIC_ACCESS_DENIED_ERROR, "ADMIN");
         }
 
-        if (type != ConfigType.FRONTEND) {
+        if (type != NodeType.FRONTEND) {
             throw new AnalysisException("Only support setting Frontend configs now");
         }
     }

fe/fe-core/src/main/java/org/apache/doris/analysis/ShowConfigStmt.java

@@ -17,67 +17,94 @@
 
 package org.apache.doris.analysis;
 
-import org.apache.doris.analysis.AdminSetConfigStmt.ConfigType;
 import org.apache.doris.catalog.Column;
 import org.apache.doris.catalog.Env;
 import org.apache.doris.catalog.ScalarType;
-import org.apache.doris.common.AnalysisException;
 import org.apache.doris.common.ErrorCode;
 import org.apache.doris.common.ErrorReport;
 import org.apache.doris.common.UserException;
 import org.apache.doris.mysql.privilege.PrivPredicate;
 import org.apache.doris.qe.ConnectContext;
 import org.apache.doris.qe.ShowResultSetMetaData;
+import org.apache.doris.system.NodeType;
 
 import com.google.common.collect.ImmutableList;
 
 // show frontend config;
-public class ShowConfigStmt extends ShowStmt {
-    public static final ImmutableList<String> TITLE_NAMES = new ImmutableList.Builder<String>().add("Key").add(
+public class ShowConfigStmt extends ShowStmt implements NotFallbackInParser {
+    public static final ImmutableList<String> FE_TITLE_NAMES = new ImmutableList.Builder<String>().add("Key").add(
             "Value").add("Type").add("IsMutable").add("MasterOnly").add("Comment").build();
 
-    private ConfigType type;
+    public static final ImmutableList<String> BE_TITLE_NAMES = new ImmutableList.Builder<String>().add("BackendId")
+            .add("Host").add("Key").add("Value").add("Type").add("IsMutable").build();
+
+    private NodeType type;
 
     private String pattern;
 
-    public ShowConfigStmt(ConfigType type, String pattern) {
+    private long backendId;
+
+    private boolean isShowSingleBackend;
+
+    public ShowConfigStmt(NodeType type, String pattern) {
+        this.type = type;
+        this.pattern = pattern;
+    }
+
+    public ShowConfigStmt(NodeType type, String pattern, long backendId) {
         this.type = type;
         this.pattern = pattern;
+        this.backendId = backendId;
+        this.isShowSingleBackend = true;
     }
 
-    public ConfigType getType() {
+    public NodeType getType() {
         return type;
     }
 
     public String getPattern() {
         return pattern;
     }
 
+    public long getBackendId() {
+        return backendId;
+    }
+
+    public boolean isShowSingleBackend() {
+        return isShowSingleBackend;
+    }
+
     @Override
-    public void analyze(Analyzer analyzer) throws AnalysisException, UserException {
+    public void analyze(Analyzer analyzer) throws UserException {
         super.analyze(analyzer);
 
         // check auth
         if (!Env.getCurrentEnv().getAccessManager().checkGlobalPriv(ConnectContext.get(), PrivPredicate.ADMIN)) {
             ErrorReport.reportAnalysisException(ErrorCode.ERR_SPECIFIC_ACCESS_DENIED_ERROR, "ADMIN");
         }
-
-        if (type != ConfigType.FRONTEND) {
-            throw new AnalysisException("Only support setting Frontend configs now");
-        }
     }
 
     @Override
     public ShowResultSetMetaData getMetaData() {
         ShowResultSetMetaData.Builder builder = ShowResultSetMetaData.builder();
-        for (String title : TITLE_NAMES) {
-            builder.addColumn(new Column(title, ScalarType.createVarchar(30)));
+        if (type == NodeType.FRONTEND) {
+            for (String title : FE_TITLE_NAMES) {
+                builder.addColumn(new Column(title, ScalarType.createVarchar(30)));
+            }
+        } else {
+            for (String title : BE_TITLE_NAMES) {
+                builder.addColumn(new Column(title, ScalarType.createVarchar(30)));
+            }
         }
         return builder.build();
     }
 
     @Override
     public RedirectStatus getRedirectStatus() {
+        // no need forward to master for backend config
+        if (type == NodeType.BACKEND) {
+            return RedirectStatus.NO_FORWARD;
+        }
         if (ConnectContext.get().getSessionVariable().getForwardToMaster()) {
             return RedirectStatus.FORWARD_NO_SYNC;
         } else {

fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java

@@ -172,6 +172,7 @@
 import org.apache.doris.nereids.DorisParser.SelectColumnClauseContext;
 import org.apache.doris.nereids.DorisParser.SelectHintContext;
 import org.apache.doris.nereids.DorisParser.SetOperationContext;
+import org.apache.doris.nereids.DorisParser.ShowConfigContext;
 import org.apache.doris.nereids.DorisParser.ShowConstraintContext;
 import org.apache.doris.nereids.DorisParser.ShowCreateMTMVContext;
 import org.apache.doris.nereids.DorisParser.ShowCreateProcedureContext;
@@ -390,6 +391,7 @@
 import org.apache.doris.nereids.trees.plans.commands.PauseMTMVCommand;
 import org.apache.doris.nereids.trees.plans.commands.RefreshMTMVCommand;
 import org.apache.doris.nereids.trees.plans.commands.ResumeMTMVCommand;
+import org.apache.doris.nereids.trees.plans.commands.ShowConfigCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowConstraintsCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowCreateMTMVCommand;
 import org.apache.doris.nereids.trees.plans.commands.ShowCreateProcedureCommand;
@@ -472,6 +474,7 @@
 import org.apache.doris.policy.PolicyTypeEnum;
 import org.apache.doris.qe.ConnectContext;
 import org.apache.doris.qe.SqlModeHelper;
+import org.apache.doris.system.NodeType;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -3677,4 +3680,24 @@ public LogicalPlan visitCreateTableLike(CreateTableLikeContext ctx) {
                 rollupNames, withAllRollUp);
         return new CreateTableLikeCommand(info);
     }
+
+    @Override
+    public LogicalPlan visitShowConfig(ShowConfigContext ctx) {
+        ShowConfigCommand command;
+        if (ctx.type.getText().equalsIgnoreCase(NodeType.FRONTEND.name())) {
+            command = new ShowConfigCommand(NodeType.FRONTEND);
+        } else {
+            command = new ShowConfigCommand(NodeType.BACKEND);
+        }
+        if (ctx.LIKE() != null && ctx.pattern != null) {
+            Like like = new Like(new UnboundSlot("ProcedureName"), getExpression(ctx.pattern));
+            String pattern = ((Literal) like.child(1)).getStringValue();
+            command.setPattern(pattern);
+        }
+        if (ctx.FROM() != null && ctx.backendId != null) {
+            long backendId = Long.parseLong(ctx.backendId.getText());
+            command.setBackendId(backendId);
+        }
+        return command;
+    }
 }

fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/PlanType.java

@@ -163,5 +163,6 @@ public enum PlanType {
     CREATE_TABLE_LIKE_COMMAND,
 
     PREPARED_COMMAND,
-    EXECUTE_COMMAND
+    EXECUTE_COMMAND,
+    SHOW_CONFIG_COMMAND
 }