Verify the instanceId size
diff --git a/omega/omega-context/src/main/java/org/apache/servicecomb/pack/omega/context/ServiceConfig.java b/omega/omega-context/src/main/java/org/apache/servicecomb/pack/omega/context/ServiceConfig.java
index 09024e6..d9b0aa0 100644
--- a/omega/omega-context/src/main/java/org/apache/servicecomb/pack/omega/context/ServiceConfig.java
+++ b/omega/omega-context/src/main/java/org/apache/servicecomb/pack/omega/context/ServiceConfig.java
@@ -23,12 +23,14 @@
 public class ServiceConfig {
   private final String serviceName;
   private final String instanceId;
+  // Current DB only supports instance id less then 35
+  private static final int MAX_LENGTH = 35;
 
   public ServiceConfig(String serviceName) {
     this(serviceName,null);
   }
 
-  public ServiceConfig(String serviceName,String instanceId) {
+  public ServiceConfig(String serviceName, String instanceId) {
     this.serviceName = serviceName;
     if(instanceId == null || "".equalsIgnoreCase(instanceId.trim())){
       try {
@@ -37,6 +39,10 @@
         throw new IllegalStateException(e);
       }
     }else{
+      instanceId = instanceId.trim();
+      if (instanceId.length() > MAX_LENGTH) {
+        throw new IllegalArgumentException(String.format("The instanceId length exceeds maximum length limit [%d].", MAX_LENGTH));
+      }
       this.instanceId = instanceId;
     }
   }