From 660072df1379757b41a21c2dcc289b3ae926ded0 Mon Sep 17 00:00:00 2001
From: Steven Murray <steven.murray@cern.ch>
Date: Tue, 6 Dec 2016 10:47:41 +0100
Subject: [PATCH] Bare minimum database reconnect logic
---
rdbms/Conn.cpp | 14 ++++++++++++++
rdbms/Conn.hpp | 24 ++++++++++++++++++++++++
rdbms/ConnPool.cpp | 22 ++++++++++++++++++----
rdbms/ConnPool.hpp | 7 +++++--
rdbms/OcciConn.cpp | 35 +++++++++++++++++++++++++++++++++++
rdbms/OcciConn.hpp | 10 ++++++++++
rdbms/OcciStmt.cpp | 17 ++++++-----------
7 files changed, 112 insertions(+), 17 deletions(-)
diff --git a/rdbms/Conn.cpp b/rdbms/Conn.cpp
index f70c14b855..75462ba85c 100644
--- a/rdbms/Conn.cpp
+++ b/rdbms/Conn.cpp
@@ -67,5 +67,19 @@ void Conn::executeNonQuery(const std::string &sql, const Stmt::AutocommitMode au
}
}
+//------------------------------------------------------------------------------
+// setHealthy
+//------------------------------------------------------------------------------
+void Conn::setHealthy(const bool value) {
+ m_healthy = value;
+}
+
+//------------------------------------------------------------------------------
+// getHealthy
+//------------------------------------------------------------------------------
+bool Conn::getHealthy() const {
+ return m_healthy;
+}
+
} // namespace rdbms
} // namespace cta
diff --git a/rdbms/Conn.hpp b/rdbms/Conn.hpp
index 7a9f08f051..684b97e58c 100644
--- a/rdbms/Conn.hpp
+++ b/rdbms/Conn.hpp
@@ -20,6 +20,7 @@
#include "Stmt.hpp"
+#include <atomic>
#include <list>
#include <memory>
#include <string>
@@ -93,6 +94,29 @@ public:
*/
virtual std::list<std::string> getTableNames() = 0;
+ /**
+ * Returns true if the connection is healthy.
+ *
+ * @return True if the connection is healthy.
+ */
+ bool getHealthy() const;
+
+protected:
+
+ /**
+ * Sets the status of the connection to be either healthy or not healthy.
+ *
+ * @param value True if the connection is healthy.
+ */
+ void setHealthy(const bool value);
+
+private:
+
+ /**
+ * True if the connection's state is healthy.
+ */
+ std::atomic<bool> m_healthy{true};
+
}; // class Conn
} // namespace rdbms
diff --git a/rdbms/ConnPool.cpp b/rdbms/ConnPool.cpp
index ed75b79df1..e9101aa26e 100644
--- a/rdbms/ConnPool.cpp
+++ b/rdbms/ConnPool.cpp
@@ -69,10 +69,24 @@ PooledConn ConnPool::getConn() {
// returnConn
//------------------------------------------------------------------------------
void ConnPool::returnConn(Conn *const conn) {
- conn->commit();
- std::unique_lock<std::mutex> lock(m_connsMutex);
- m_conns.emplace_back(conn);
- m_connsCv.notify_one();
+ // If the connection is healthy
+ if(conn->getHealthy()) {
+
+ // Commit the connection and put it back in the pool
+ conn->commit();
+ std::unique_lock<std::mutex> lock(m_connsMutex);
+ m_conns.emplace_back(conn);
+ m_connsCv.notify_one();
+
+ // Else the connection is not healthy
+ } else {
+
+ // Close the connection and put a brand new one in the pool
+ delete conn;
+ std::unique_lock<std::mutex> lock(m_connsMutex);
+ m_conns.push_back(m_connFactory.create());
+ m_connsCv.notify_one();
+ }
}
} // namespace rdbms
diff --git a/rdbms/ConnPool.hpp b/rdbms/ConnPool.hpp
index 7cf1c0c020..c3fa7ce853 100644
--- a/rdbms/ConnPool.hpp
+++ b/rdbms/ConnPool.hpp
@@ -60,8 +60,11 @@ private:
friend PooledConn;
/**
- * Calls commit on the specified database connection and returns it to the
- * pool.
+ * If the specified database connection is healthy, then this method calls
+ * commit on the connection and returns it to the pool.
+ *
+ * If the specified database connection is no healthy, then this method
+ * closes the connection and creates a new one in the connection pool.
*
* @param conn The connection to be commited and returned to the pool.
*/
diff --git a/rdbms/OcciConn.cpp b/rdbms/OcciConn.cpp
index a379fab4a4..9b8cd0a804 100644
--- a/rdbms/OcciConn.cpp
+++ b/rdbms/OcciConn.cpp
@@ -138,5 +138,40 @@ std::list<std::string> OcciConn::getTableNames() {
}
}
+//------------------------------------------------------------------------------
+// updateHealth
+//------------------------------------------------------------------------------
+void OcciConn::updateHealth(const oracle::occi::SQLException &ex) {
+ using namespace oracle;
+
+ // Error codes that identify an unhealthy connection
+ // The majority of these error codes were learnt from CASTOR
+ switch(ex.getErrorCode()) {
+ case 28:
+ case 1003:
+ case 1008:
+ case 1012:
+ case 1033:
+ case 1089:
+ case 2392:
+ case 2399:
+ case 3113:
+ case 3114:
+ case 3135:
+ case 12170:
+ case 12541:
+ case 12571:
+ case 24338:
+ case 12537:
+ case 25401:
+ case 25409:
+ case 32102:
+ setHealthy(false);
+ break;
+ default:
+ break;
+ };
+}
+
} // namespace rdbms
} // namespace cta
diff --git a/rdbms/OcciConn.hpp b/rdbms/OcciConn.hpp
index d922bf7ce2..59c01ee0fa 100644
--- a/rdbms/OcciConn.hpp
+++ b/rdbms/OcciConn.hpp
@@ -105,6 +105,8 @@ public:
private:
+ friend OcciStmt;
+
/**
* Mutex used to serialize access to this object.
*/
@@ -120,6 +122,14 @@ private:
*/
oracle::occi::Connection *m_conn;
+ /**
+ * Determines whether or not the specified Oracle exception affects the status
+ * of the database connection and updates it accordingly.
+ *
+ * @param ex The Oracle exception.
+ */
+ void updateHealth(const oracle::occi::SQLException &ex);
+
}; // class OcciConn
} // namespace rdbms
diff --git a/rdbms/OcciStmt.cpp b/rdbms/OcciStmt.cpp
index af81221ba2..2aaf5583aa 100644
--- a/rdbms/OcciStmt.cpp
+++ b/rdbms/OcciStmt.cpp
@@ -23,7 +23,6 @@
#include "rdbms/OcciStmt.hpp"
#include <cstring>
-#include <iostream>
#include <map>
#include <sstream>
#include <stdexcept>
@@ -181,11 +180,9 @@ std::unique_ptr<Rset> OcciStmt::executeQuery() {
try {
return cta::make_unique<OcciRset>(*this, m_stmt->executeQuery());
- } catch(exception::Exception &ex) {
- throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " +
- ex.getMessage().str());
- } catch(std::exception &se) {
- throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " + se.what());
+ } catch(occi::SQLException &ex) {
+ m_conn.updateHealth(ex);
+ throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " + ex.what());
}
}
@@ -197,11 +194,9 @@ void OcciStmt::executeNonQuery() {
try {
m_stmt->executeUpdate();
- } catch(exception::Exception &ex) {
- throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " +
- ex.getMessage().str());
- } catch(std::exception &se) {
- throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " + se.what());
+ } catch(occi::SQLException &ex) {
+ m_conn.updateHealth(ex);
+ throw exception::Exception(std::string(__FUNCTION__) + " failed for SQL statement " + getSql() + ": " + ex.what());
}
}
--
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