lb.h

/*
OpenIO SDS metautils
Copyright (C) 2014 Worldline, as part of Redcurrant
Copyright (C) 2015-2019 OpenIO SAS, as part of OpenIO SDS

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3.0 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library.
*/

#ifndef OIO_SDS__metautils__lib__lb_h
# define OIO_SDS__metautils__lib__lb_h 1

#include <metautils/lib/metatypes.h>

struct namespace_info_s;

/* -- New style load balancing -------------------------------------------- */

/** Insert or update a list of services in a LB world */
void oio_lb_world__feed_service_info_list(struct oio_lb_world_s *lbw,
		GSList *services);

/** Insert or update a list of services in a LB world.
 * Each line of the string should contain a service ID (or address),
 * and optionally (space separated):
 * - a location;
 * - a score;
 * - an additional slot. */
void oio_lb_world__feed_from_string(struct oio_lb_world_s *self,
		const gchar *main_slot, const gchar *file_contents);

/** Insert or update a list of services in a LB world.
 * Each line of the file should contain a service ID (or address),
 * and optionally (space separated):
 * - a location;
 * - a score;
 * - an additional slot. */
GError *oio_lb_world__feed_from_file(struct oio_lb_world_s *self,
		const gchar *main_slot, const gchar *src_file);

/** Check there is a pool for each storage policy. If not,
 * create a service pool returning sets of services satisfying
 * the specified storage policy */
void oio_lb_world__reload_storage_policies(struct oio_lb_world_s *lbw,
		struct oio_lb_s *lb, struct namespace_info_s *nsinfo);

/** Create service pools from string definitions. */
void oio_lb_world__reload_pools(struct oio_lb_world_s *lbw,
		struct oio_lb_s *lb, struct namespace_info_s *nsinfo);

/** Check how many times each service has been selected.
 * `counts` is a hash table with service IDs as keys and the number
 * of times they have been selected as values. */
void oio_lb_world__check_repartition(struct oio_lb_world_s *world,
		int targets, int shots, GHashTable *counts);

/** Create a service pool returning sets of services satisfying
 * the specified service update policy */
struct oio_lb_pool_s *oio_lb_pool__from_service_policy(
		struct oio_lb_world_s *lbw,
		const gchar *srvtype,
		struct service_update_policies_s *pols);

/* Repeatedly call oio_lb_pool__poll(), check for unbalanced situations,
 * and count how many times each service has been selected. */
void oio_lb_pool__poll_many(struct oio_lb_pool_s *pool, int iterations,
		GHashTable *services, int *unbalanced_situations);

#endif /*OIO_SDS__metautils__lib__lb_h*/