MaxScale/server/include/server.h

#ifndef _SERVER_H
#define _SERVER_H
/*
 * Copyright (c) 2016 MariaDB Corporation Ab
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file and at www.mariadb.com/bsl.
 *
 * Change Date: 2019-07-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2 or later of the General
 * Public License.
 */
#include <dcb.h>
#include <resultset.h>

/**
 * @file service.h
 *
 * The server level definitions within the gateway
 *
 * @verbatim
 * Revision History
 *
 * Date         Who                     Description
 * 14/06/13     Mark Riddoch            Initial implementation
 * 21/06/13     Mark Riddoch            Addition of server status flags
 * 22/07/13     Mark Riddoch            Addition of JOINED status for Galera
 * 18/05/14     Mark Riddoch            Addition of unique_name field
 * 20/05/14     Massimiliano Pinto      Addition of server_string field
 * 20/05/14     Massimiliano Pinto      Addition of node_id field
 * 23/05/14     Massimiliano Pinto      Addition of rlag and node_ts fields
 * 03/06/14     Mark Riddoch            Addition of maintainance mode
 * 20/06/14     Massimiliano Pinto      Addition of master_id, depth, slaves fields
 * 26/06/14     Mark Riddoch            Adidtion of server parameters
 * 30/07/14     Massimiliano Pinto      Addition of NDB status for MySQL Cluster
 * 30/08/14     Massimiliano Pinto      Addition of SERVER_STALE_STATUS
 * 27/10/14     Massimiliano Pinto      Addition of SERVER_MASTER_STICKINESS
 * 19/02/15     Mark Riddoch            Addition of serverGetList
 * 01/06/15     Massimiliano Pinto      Addition of server_update_address/port
 * 19/06/15     Martin Brampton         Extra fields for persistent connections, CHK_SERVER
 *
 * @endverbatim
 */

#define MAX_SERVER_NAME_LEN 1024

/**
 * The server parameters used for weighting routing decissions
 *
 */
typedef struct server_params
{
    char *name;                 /**< Parameter name */
    char *value;                /**< Parameter value */
    struct server_params *next; /**< Next Paramter in the linked list */
} SERVER_PARAM;

/**
 * The server statistics structure
 *
 */
typedef struct
{
    int n_connections; /**< Number of connections */
    int n_current;     /**< Current connections */
    int n_current_ops; /**< Current active operations */
    int n_persistent;  /**< Current persistent pool */
} SERVER_STATS;

/**
 * The SERVER structure defines a backend server. Each server has a name
 * or IP address for the server, a port that the server listens on and
 * the name of a protocol module that is loaded to implement the protocol
 * between the gateway and the server.
 */
typedef struct server
{
#if defined(SS_DEBUG)
    skygw_chk_t     server_chk_top;
#endif
    SPINLOCK       lock;           /**< Common access lock */
    char           *unique_name;   /**< Unique name for the server */
    char           *name;          /**< Server name/IP address*/
    unsigned short port;           /**< Port to listen on */
    char           *protocol;      /**< Protocol module to use */
    SSL_LISTENER   *server_ssl;    /**< SSL data structure for server, if any */
    unsigned int   status;         /**< Status flag bitmap for the server */
    char           *monuser;       /**< User name to use to monitor the db */
    char           *monpw;         /**< Password to use to monitor the db */
    SERVER_STATS   stats;          /**< The server statistics */
    struct  server *next;          /**< Next server */
    struct  server *nextdb;        /**< Next server in list attached to a service */
    char           *server_string; /**< Server version string, i.e. MySQL server version */
    long           node_id;        /**< Node id, server_id for M/S or local_index for Galera */
    int            rlag;           /**< Replication Lag for Master / Slave replication */
    unsigned long  node_ts;        /**< Last timestamp set from M/S monitor module */
    SERVER_PARAM   *parameters;    /**< Parameters of a server that may be used to weight routing decisions */
    long           master_id;      /**< Master server id of this node */
    int            depth;          /**< Replication level in the tree */
    long           *slaves;        /**< Slaves of this node */
    bool           master_err_is_logged; /*< If node failed, this indicates whether it is logged */
    DCB            *persistent;    /**< List of unused persistent connections to the server */
    SPINLOCK       persistlock;    /**< Lock for adjusting the persistent connections list */
    long           persistpoolmax; /**< Maximum size of persistent connections pool */
    long           persistmaxtime; /**< Maximum number of seconds connection can live */
    int            persistmax;     /**< Maximum pool size actually achieved since startup */
#if defined(SS_DEBUG)
    skygw_chk_t    server_chk_tail;
#endif
} SERVER;

/**
 * Status bits in the server->status member.
 *
 * These are a bitmap of attributes that may be applied to a server
 */
#define SERVER_RUNNING           0x0001  /**<< The server is up and running */
#define SERVER_MASTER            0x0002  /**<< The server is a master, i.e. can handle writes */
#define SERVER_SLAVE             0x0004  /**<< The server is a slave, i.e. can handle reads */
#define SERVER_JOINED            0x0008  /**<< The server is joined in a Galera cluster */
#define SERVER_NDB               0x0010  /**<< The server is part of a MySQL cluster setup */
#define SERVER_MAINT             0x0020  /**<< Server is in maintenance mode */
#define SERVER_SLAVE_OF_EXTERNAL_MASTER  0x0040 /**<< Server is slave of a Master outside
                                                   the provided replication topology */
#define SERVER_STALE_STATUS      0x0080  /**<< Server stale status, monitor didn't update it */
#define SERVER_MASTER_STICKINESS 0x0100  /**<< Server Master stickiness */
#define SERVER_AUTH_ERROR        0x1000  /**<< Authentication error from monitor */
#define SERVER_STALE_SLAVE       0x2000  /**<< Slave status is possible even without a master */

/**
 * Is the server running - the macro returns true if the server is marked as running
 * regardless of it's state as a master or slave
 */
#define SERVER_IS_RUNNING(server) (((server)->status & (SERVER_RUNNING|SERVER_MAINT)) == SERVER_RUNNING)
/**
 * Is the server marked as down - the macro returns true if the server is believed
 * to be inoperable.
 */
#define SERVER_IS_DOWN(server)          (((server)->status & SERVER_RUNNING) == 0)
/**
 * Is the server a master? The server must be both running and marked as master
 * in order for the macro to return true
 */
#define SERVER_IS_MASTER(server) SRV_MASTER_STATUS((server)->status)

#define SRV_MASTER_STATUS(status) ((status &                            \
                                    (SERVER_RUNNING|SERVER_MASTER|SERVER_MAINT)) == \
                                   (SERVER_RUNNING|SERVER_MASTER))

/**
 * Is the server valid candidate for root master. The server must be running,
 * marked as master and not have maintenance bit set.
 */
#define SERVER_IS_ROOT_MASTER(server)                                   \
    (((server)->status & (SERVER_RUNNING|SERVER_MASTER|SERVER_MAINT)) == (SERVER_RUNNING|SERVER_MASTER))

/**
 * Is the server a slave? The server must be both running and marked as a slave
 * in order for the macro to return true
 */
#define SERVER_IS_SLAVE(server)                                         \
    (((server)->status & (SERVER_RUNNING|SERVER_SLAVE|SERVER_MAINT)) == \
     (SERVER_RUNNING|SERVER_SLAVE))

/**
 * Is the server joined Galera node? The server must be running and joined.
 */
#define SERVER_IS_JOINED(server)                                        \
    (((server)->status & (SERVER_RUNNING|SERVER_JOINED|SERVER_MAINT)) == (SERVER_RUNNING|SERVER_JOINED))

/**
 * Is the server a SQL node in MySQL Cluster? The server must be running and with NDB status
 */
#define SERVER_IS_NDB(server)                                           \
    (((server)->status & (SERVER_RUNNING|SERVER_NDB|SERVER_MAINT)) == (SERVER_RUNNING|SERVER_NDB))

/**
 * Is the server in maintenance mode.
 */
#define SERVER_IN_MAINT(server)         ((server)->status & SERVER_MAINT)

/** server is not master, slave or joined */
#define SERVER_NOT_IN_CLUSTER(s) (((s)->status & (SERVER_MASTER|SERVER_SLAVE|SERVER_JOINED|SERVER_NDB)) == 0)

#define SERVER_IS_IN_CLUSTER(s)  (((s)->status & (SERVER_MASTER|SERVER_SLAVE|SERVER_JOINED|SERVER_NDB)) != 0)

#define SERVER_IS_RELAY_SERVER(server)                                  \
    (((server)->status & (SERVER_RUNNING|SERVER_MASTER|SERVER_SLAVE|SERVER_MAINT)) == \
     (SERVER_RUNNING|SERVER_MASTER|SERVER_SLAVE))

extern SERVER *server_alloc(char *, char *, unsigned short);
extern int server_free(SERVER *);
extern SERVER *server_find_by_unique_name(char *);
extern SERVER *server_find(char *, unsigned short);
extern void printServer(SERVER *);
extern void printAllServers();
extern void dprintAllServers(DCB *);
extern void dprintAllServersJson(DCB *);
extern void dprintServer(DCB *, SERVER *);
extern void dprintPersistentDCBs(DCB *, SERVER *);
extern void dListServers(DCB *);
extern char *server_status(SERVER *);
extern void server_clear_set_status(SERVER *server, int specified_bits, int bits_to_set);
extern void server_set_status(SERVER *, int);
extern void server_clear_status(SERVER *, int);
extern void server_transfer_status(SERVER *dest_server, SERVER *source_server);
extern void serverAddMonUser(SERVER *, char *, char *);
extern void serverAddParameter(SERVER *, char *, char *);
extern char *serverGetParameter(SERVER *, char *);
extern void server_update(SERVER *, char *, char *, char *);
extern void server_set_unique_name(SERVER *, char *);
extern DCB  *server_get_persistent(SERVER *, char *, const char *);
extern void server_update_address(SERVER *, char *);
extern void server_update_port(SERVER *,  unsigned short);
extern RESULTSET *serverGetList();
extern unsigned int server_map_status(char *str);
extern bool server_set_version_string(SERVER* server, const char* string);

#endif