From 2d1bbbb08b3fd6065805dc229059c5e6455cf612 Mon Sep 17 00:00:00 2001
From: Jeff Zhang <zjffdu@apache.org>
Date: Thu, 24 May 2018 16:10:47 +0800
Subject: [PATCH] ZEPPELIN-3497. Improve error message when livy session is
 failed to create

---
 .../zeppelin/livy/BaseLivyInterpreter.java    | 26 +++++++++++++++++--
 .../main/resources/interpreter-setting.json   |  6 +++++
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java b/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
index 9d2c0cfa93e..eef5f5caf71 100644
--- a/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
+++ b/livy/src/main/java/org/apache/zeppelin/livy/BaseLivyInterpreter.java
@@ -94,6 +94,7 @@ public abstract class BaseLivyInterpreter extends Interpreter {
   private String livyURL;
   private int sessionCreationTimeout;
   private int pullStatusInterval;
+  private int maxLogLines;
   protected boolean displayAppInfo;
   private boolean restartDeadSession;
   protected LivyVersion livyVersion;
@@ -119,6 +120,8 @@ public BaseLivyInterpreter(Properties property) {
         property.getProperty("zeppelin.livy.session.create_timeout", 120 + ""));
     this.pullStatusInterval = Integer.parseInt(
         property.getProperty("zeppelin.livy.pull_status.interval.millis", 1000 + ""));
+    this.maxLogLines = Integer.parseInt(property.getProperty("zeppelin.livy.maxLogLines",
+        "1000"));
     this.restTemplate = createRestTemplate();
     if (!StringUtils.isBlank(property.getProperty("zeppelin.livy.http.headers"))) {
       String[] headers = property.getProperty("zeppelin.livy.http.headers").split(";");
@@ -338,7 +341,7 @@ private SessionInfo createSession(String user, String kind)
         if ((System.currentTimeMillis() - start) / 1000 > sessionCreationTimeout) {
           String msg = "The creation of session " + sessionInfo.id + " is timeout within "
               + sessionCreationTimeout + " seconds, appId: " + sessionInfo.appId
-              + ", log: " + sessionInfo.log;
+              + ", log:\n" + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
           throw new LivyException(msg);
         }
         Thread.sleep(pullStatusInterval);
@@ -347,7 +350,7 @@ private SessionInfo createSession(String user, String kind)
             sessionInfo.appId);
         if (sessionInfo.isFinished()) {
           String msg = "Session " + sessionInfo.id + " is finished, appId: " + sessionInfo.appId
-              + ", log: " + sessionInfo.log;
+              + ", log:\n" + StringUtils.join(getSessionLog(sessionInfo.id).log, "\n");
           throw new LivyException(msg);
         }
       }
@@ -362,6 +365,11 @@ private SessionInfo getSessionInfo(int sessionId) throws LivyException {
     return SessionInfo.fromJson(callRestAPI("/sessions/" + sessionId, "GET"));
   }
 
+  private SessionLog getSessionLog(int sessionId) throws LivyException {
+    return SessionLog.fromJson(callRestAPI("/sessions/" + sessionId + "/log?size=" + maxLogLines,
+        "GET"));
+  }
+
   public InterpreterResult interpret(String code,
                                      String paragraphId,
                                      boolean displayAppInfo,
@@ -822,6 +830,20 @@ public static SessionInfo fromJson(String json) {
     }
   }
 
+  private static class SessionLog {
+    public int id;
+    public int from;
+    public int size;
+    public List<String> log;
+
+    SessionLog() {
+    }
+
+    public static SessionLog fromJson(String json) {
+      return gson.fromJson(json, SessionLog.class);
+    }
+  }
+
   static class ExecuteRequest {
     public final String code;
     public final String kind;
diff --git a/livy/src/main/resources/interpreter-setting.json b/livy/src/main/resources/interpreter-setting.json
index 8b9b90613a2..a7ce2b38454 100644
--- a/livy/src/main/resources/interpreter-setting.json
+++ b/livy/src/main/resources/interpreter-setting.json
@@ -97,6 +97,12 @@
         "description": "The interval for checking paragraph execution status",
         "type": "number"
       },
+      "zeppelin.livy.maxLogLines": {
+        "propertyName": "zeppelin.livy.maxLogLines",
+        "defaultValue": "1000",
+        "description": "Max number of lines of logs",
+        "type": "number"
+      },
       "livy.spark.jars.packages": {
         "propertyName": "livy.spark.jars.packages",
         "defaultValue": "",