[ISSUE #10510] Add gRPC server permit keepalive configuration (#10516)

proxy/src/main/java/org/apache/rocketmq/proxy/config/ProxyConfig.java

@@ -156,6 +156,8 @@ public class ProxyConfig implements ConfigFile {
     private long grpcClientConsumerMaxLongPollingTimeoutMillis = Duration.ofSeconds(20).toMillis();
     private int grpcClientConsumerLongPollingBatchSize = 32;
     private long grpcClientIdleTimeMills = Duration.ofSeconds(120).toMillis();
+    private long grpcServerPermitKeepAliveTimeMillis = 30000;
+    private boolean grpcServerPermitKeepAliveWithoutCalls = true;
 
     private int channelExpiredInSeconds = 60;
     private int contextExpiredInSeconds = 30;
@@ -1221,6 +1223,22 @@ public class ProxyConfig implements ConfigFile {
         this.grpcClientIdleTimeMills = grpcClientIdleTimeMills;
     }
 
+    public long getGrpcServerPermitKeepAliveTimeMillis() {
+        return grpcServerPermitKeepAliveTimeMillis;
+    }
+
+    public void setGrpcServerPermitKeepAliveTimeMillis(long grpcServerPermitKeepAliveTimeMillis) {
+        this.grpcServerPermitKeepAliveTimeMillis = grpcServerPermitKeepAliveTimeMillis;
+    }
+
+    public boolean isGrpcServerPermitKeepAliveWithoutCalls() {
+        return grpcServerPermitKeepAliveWithoutCalls;
+    }
+
+    public void setGrpcServerPermitKeepAliveWithoutCalls(boolean grpcServerPermitKeepAliveWithoutCalls) {
+        this.grpcServerPermitKeepAliveWithoutCalls = grpcServerPermitKeepAliveWithoutCalls;
+    }
+
     public String getRegionId() {
         return regionId;
     }

proxy/src/main/java/org/apache/rocketmq/proxy/grpc/GrpcServerBuilder.java

@@ -78,7 +78,9 @@ public class GrpcServerBuilder {
         }
 
         serverBuilder.maxInboundMessageSize(maxInboundMessageSize)
-            .maxConnectionIdle(idleTimeMills, TimeUnit.MILLISECONDS);
+            .maxConnectionIdle(idleTimeMills, TimeUnit.MILLISECONDS)
+            .permitKeepAliveTime(config.getGrpcServerPermitKeepAliveTimeMillis(), TimeUnit.MILLISECONDS)
+            .permitKeepAliveWithoutCalls(config.isGrpcServerPermitKeepAliveWithoutCalls());
 
         log.info("grpc server has built. port: {}, bossLoopNum: {}, workerLoopNum: {}, maxInboundMessageSize: {}",
             port, bossLoopNum, workerLoopNum, maxInboundMessageSize);