From af3e2c429f23acc605fcf83e7b720d6c6c1eceed Mon Sep 17 00:00:00 2001
From: Michael Friedrich <michael.friedrich@icinga.com>
Date: Fri, 24 Mar 2017 15:18:37 +0100
Subject: [PATCH] Add exception handler for Redis WorkQueue

refs #4991
---
 lib/redis/rediswriter.cpp | 17 ++++++++++++++++-
 lib/redis/rediswriter.hpp |  2 ++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/lib/redis/rediswriter.cpp b/lib/redis/rediswriter.cpp
index 010499387..0674f9d62 100644
--- a/lib/redis/rediswriter.cpp
+++ b/lib/redis/rediswriter.cpp
@@ -42,6 +42,8 @@ void RedisWriter::Start(bool runtimeCreated)
 
 	m_ConfigDumpInProgress = false;
 
+	m_WorkQueue.SetExceptionCallback(boost::bind(&RedisWriter::ExceptionHandler, this, _1));
+
 	m_ReconnectTimer = new Timer();
 	m_ReconnectTimer->SetInterval(15);
 	m_ReconnectTimer->OnTimerExpired.connect(boost::bind(&RedisWriter::ReconnectTimerHandler, this));
@@ -57,6 +59,19 @@ void RedisWriter::Start(bool runtimeCreated)
 	thread.detach();
 }
 
+void RedisWriter::ExceptionHandler(boost::exception_ptr exp)
+{
+	Log(LogCritical, "RedisWriter", "Exception during redis query. Verify that Redis is operational.");
+
+	Log(LogDebug, "RedisWriter")
+	    << "Exception during redis operation: " << DiagnosticInformation(exp);
+
+	if (m_Context) {
+		redisFree(m_Context);
+		m_Context = NULL;
+	}
+}
+
 void RedisWriter::ReconnectTimerHandler(void)
 {
 	m_WorkQueue.Enqueue(boost::bind(&RedisWriter::TryToReconnect, this));
@@ -275,7 +290,7 @@ boost::shared_ptr<redisReply> RedisWriter::ExecuteQuery(const std::vector<String
 	delete [] argvlen;
 
 	if (reply->type == REDIS_REPLY_ERROR) {
-		Log(LogInformation, "RedisWriter")
+		Log(LogCritical, "RedisWriter")
 		    << "Redis query failed: " << reply->str;
 
 		String msg = reply->str;
diff --git a/lib/redis/rediswriter.hpp b/lib/redis/rediswriter.hpp
index a32304f0b..04af7c520 100644
--- a/lib/redis/rediswriter.hpp
+++ b/lib/redis/rediswriter.hpp
@@ -82,6 +82,8 @@ private:
 
 	void AssertOnWorkQueue(void);
 
+	void ExceptionHandler(boost::exception_ptr exp);
+
 	boost::shared_ptr<redisReply> ExecuteQuery(const std::vector<String>& query);
 
 	Timer::Ptr m_ReconnectTimer;