haproxy/include/proto/stick_table.h
Willy Tarreau 3a925c155d MEDIUM: stick-tables: flush old entries upon soft-stop
When a process with large stick tables is replaced by a new one and remains
present until the last connection finishes, it keeps these data in memory
for nothing since they will never be used anymore by incoming connections,
except during syncing with the new process. This is especially problematic
when dealing with long session protocols such as WebSocket as it becomes
possible to stack many processes and eat a lot of memory.

So the idea here is to know if a table still needs to be synced or not,
and to purge all unused entries once the sync is complete. This means that
after a few hundred milliseconds when everything has been synchronized with
the new process, only a few entries will remain allocated (only the ones
held by sessions during the restart) and all the remaining memory will be
freed.

Note that we carefully do that only after the grace period is expired so as
not to impact a possible proxy that needs to accept a few more connections
before leaving.

Doing this required to add a sync counter to the stick tables, to know how
many peer sync sessions are still in progress in order not to flush the entries
until all synchronizations are completed.
2013-09-04 17:54:01 +02:00

137 lines
4.6 KiB
C

/*
* include/proto/stick_table.h
* Functions for stick tables management.
*
* Copyright (C) 2009-2010 EXCELIANCE, Emeric Brun <ebrun@exceliance.fr>
* Copyright (C) 2010 Willy Tarreau <w@1wt.eu>
*
* 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, version 2.1
* exclusively.
*
* 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; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _PROTO_STICK_TABLE_H
#define _PROTO_STICK_TABLE_H
#include <common/errors.h>
#include <common/ticks.h>
#include <common/time.h>
#include <types/stick_table.h>
#define stktable_data_size(type) (sizeof(((union stktable_data*)0)->type))
#define stktable_data_cast(ptr, type) ((union stktable_data*)(ptr))->type
extern struct stktable_key *static_table_key;
struct stksess *stksess_new(struct stktable *t, struct stktable_key *key);
void stksess_setkey(struct stktable *t, struct stksess *ts, struct stktable_key *key);
void stksess_free(struct stktable *t, struct stksess *ts);
void stksess_kill(struct stktable *t, struct stksess *ts);
int stktable_init(struct stktable *t);
int stktable_parse_type(char **args, int *idx, unsigned long *type, size_t *key_size);
struct stksess *stktable_get_entry(struct stktable *table, struct stktable_key *key);
struct stksess *stktable_store(struct stktable *t, struct stksess *ts, int local);
struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local);
struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts);
struct stksess *stktable_lookup_key(struct stktable *t, struct stktable_key *key);
struct stksess *stktable_update_key(struct stktable *table, struct stktable_key *key);
struct stktable_key *stktable_fetch_key(struct stktable *t, struct proxy *px,
struct session *l4, void *l7, unsigned int opt,
struct sample_expr *expr);
int stktable_compatible_sample(struct sample_expr *expr, unsigned long table_type);
int stktable_get_data_type(char *name);
struct proxy *find_stktable(const char *name);
int stktable_trash_oldest(struct stktable *t, int to_batch);
/* return allocation size for standard data type <type> */
static inline int stktable_type_size(int type)
{
switch(type) {
case STD_T_SINT:
case STD_T_UINT:
return sizeof(int);
case STD_T_ULL:
return sizeof(unsigned long long);
case STD_T_FRQP:
return sizeof(struct freq_ctr_period);
}
return 0;
}
/* reserve some space for data type <type>, and associate argument at <sa> if
* not NULL. Returns PE_NONE (0) if OK or an error code among :
* - PE_ENUM_OOR if <type> does not exist
* - PE_EXIST if <type> is already registered
* - PE_ARG_NOT_USE if <sa> was provided but not expected
* - PE_ARG_MISSING if <sa> was expected but not provided
*/
static inline int stktable_alloc_data_type(struct stktable *t, int type, const char *sa)
{
if (type >= STKTABLE_DATA_TYPES)
return PE_ENUM_OOR;
if (t->data_ofs[type])
/* already allocated */
return PE_EXIST;
switch (stktable_data_types[type].arg_type) {
case ARG_T_NONE:
if (sa)
return PE_ARG_NOT_USED;
break;
case ARG_T_INT:
if (!sa)
return PE_ARG_MISSING;
t->data_arg[type].i = atoi(sa);
break;
case ARG_T_DELAY:
if (!sa)
return PE_ARG_MISSING;
sa = parse_time_err(sa, &t->data_arg[type].u, TIME_UNIT_MS);
if (sa)
return PE_ARG_INVC; /* invalid char */
break;
}
t->data_size += stktable_type_size(stktable_data_types[type].std_type);
t->data_ofs[type] = -t->data_size;
return PE_NONE;
}
/* return pointer for data type <type> in sticky session <ts> of table <t>, or
* NULL if either <ts> is NULL or the type is not stored.
*/
static inline void *stktable_data_ptr(struct stktable *t, struct stksess *ts, int type)
{
if (type >= STKTABLE_DATA_TYPES)
return NULL;
if (!t->data_ofs[type]) /* type not stored */
return NULL;
if (!ts)
return NULL;
return (void *)ts + t->data_ofs[type];
}
/* kill an entry if it's expired and its ref_cnt is zero */
static inline void stksess_kill_if_expired(struct stktable *t, struct stksess *ts)
{
if (t->expire != TICK_ETERNITY && tick_is_expired(ts->expire, now_ms))
stksess_kill(t, ts);
}
#endif /* _PROTO_STICK_TABLE_H */