diff options
Diffstat (limited to 'cpp/src/qpid/client/FailoverManager.h')
-rw-r--r-- | cpp/src/qpid/client/FailoverManager.h | 59 |
1 files changed, 57 insertions, 2 deletions
diff --git a/cpp/src/qpid/client/FailoverManager.h b/cpp/src/qpid/client/FailoverManager.h index d17b8371d0..5af2a8f994 100644 --- a/cpp/src/qpid/client/FailoverManager.h +++ b/cpp/src/qpid/client/FailoverManager.h @@ -38,21 +38,75 @@ struct CannotConnectException : qpid::Exception }; /** - * Utility to handle reconnection. + * Utility to manage failover. */ class FailoverManager { public: + /** + * Interface to implement for doing work that can be resumed on + * failover + */ struct Command { + /** + * This method will be called with isRetry=false when the + * command is first executed. The session to use for the work + * will be passed to the implementing class. If the connection + * fails while the execute call is in progress, the + * FailoverManager controlling the execution will re-establish + * a connection, open a new session and call back to the + * Command implementations execute method with the new session + * and isRetry=true. + */ virtual void execute(AsyncSession& session, bool isRetry) = 0; virtual ~Command() {} }; - FailoverManager(const ConnectionSettings& settings); + struct ReconnectionStrategy + { + /** + * This method is called by the FailoverManager prior to + * establishing a connection (or re-connection) and can be + * used if the application wishes to edit or re-order the list + * which will default to the list of known brokers for the + * last connection. + */ + virtual void editUrlList(std::vector<Url>& urls) = 0; + virtual ~ReconnectionStrategy() {} + }; + + /** + * Create a manager to control failover for a logical connection. + * + * @param settings the initial connection settings + * @param strategy optional stratgey callback allowing application + * to edit or reorder the list of urls to which reconnection is + * attempted + */ + FailoverManager(const ConnectionSettings& settings, ReconnectionStrategy* strategy = 0); + /** + * Return the current connection if open or attept to reconnect to + * the specified list of urls. If no list is specified the list of + * known brokers from the last connection will be used. If no list + * is specified and this is the first connect attempt, the host + * and port from the initial settings will be used. + */ Connection& connect(std::vector<Url> brokers = std::vector<Url>()); + /** + * Return the current connection whether open or not + */ Connection& getConnection(); + /** + * Close the current connection + */ void close(); + /** + * Reliably execute the specified command. This involves creating + * a session on which to carry out the work of the command, + * handling failover occuring while exeuting that command and + * re-starting the work. + */ void execute(Command&); private: enum State {IDLE, CONNECTING, CANT_CONNECT}; @@ -60,6 +114,7 @@ class FailoverManager qpid::sys::Monitor lock; Connection connection; ConnectionSettings settings; + ReconnectionStrategy* strategy; State state; void attempt(Connection&, ConnectionSettings settings, std::vector<Url> urls); |