public boolean tryExistsCon(final BackendConnection conn, RouteResultsetNode node) { if (conn == null) { return false; } if (!conn.isFromSlaveDB() || node.canRunnINReadDB(this.autocommit)) { if (LOGGER.isDebugEnabled()) { LOGGER.debug("found connections in session to use " + conn + " for " + node); } conn.setAttachment(node); return true; } else { // slavedb connection and can't use anymore ,release it if (LOGGER.isDebugEnabled()) { LOGGER.debug( "release slave connection,can't be used in trasaction " + conn + " for " + node); } releaseConnection(node, LOGGER.isDebugEnabled(), false); } return false; }