haproxy/src/stats-file.c
Aurelien DARRAGON 75e480d107 MEDIUM: stats: avoid 1 indirection by storing the shared stats directly in counters struct
Between 3.2 and 3.3-dev we noticed a noticeable performance regression
due to stats handling. After bisecting, Willy found out that recent
work to split stats computing accross multiple thread groups (stats
sharding) was responsible for that performance regression. We're looking
at roughly 20% performance loss.

More precisely, it is the added indirections, multiplied by the number
of statistics that are updated for each request, which in the end causes
a significant amount of time being spent resolving pointers.

We noticed that the fe_counters_shared and be_counters_shared structures
which are currently allocated in dedicated memory since a0dcab5c
("MAJOR: counters: add shared counters base infrastructure")
are no longer huge since 16eb0fab31 ("MAJOR: counters: dispatch counters
over thread groups") because they now essentially hold flags plus the
per-thread group id pointer mapping, not the counters themselves.

As such we decided to try merging fe_counters_shared and
be_counters_shared in their parent structures. The cost is slight memory
overhead for the parent structure, but it allows to get rid of one
pointer indirection. This patch alone yields visible performance gains
and almost restores 3.2 stats performance.

counters_fe_shared_get() was renamed to counters_fe_shared_prepare() and
now returns either failure or success instead of a pointer because we
don't need to retrieve a shared pointer anymore, the function takes care
of initializing existing pointer.
2025-07-25 16:46:10 +02:00

444 lines
10 KiB
C

#include <haproxy/stats-file.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <import/ebmbtree.h>
#include <import/ebsttree.h>
#include <import/ist.h>
#include <haproxy/api.h>
#include <haproxy/buf.h>
#include <haproxy/chunk.h>
#include <haproxy/clock.h>
#include <haproxy/errors.h>
#include <haproxy/global.h>
#include <haproxy/guid.h>
#include <haproxy/intops.h>
#include <haproxy/list.h>
#include <haproxy/listener-t.h>
#include <haproxy/obj_type.h>
#include <haproxy/proxy-t.h>
#include <haproxy/server-t.h>
#include <haproxy/stats.h>
#include <haproxy/time.h>
/* Dump all fields from <stats> into <out> for stats-file. */
int stats_dump_fields_file(struct buffer *out,
const struct field *line, size_t stats_count,
struct show_stat_ctx *ctx)
{
struct guid_node *guid;
struct listener *l;
int i;
switch (ctx->px_st) {
case STAT_PX_ST_FE:
case STAT_PX_ST_BE:
guid = &__objt_proxy(ctx->obj1)->guid;
break;
case STAT_PX_ST_LI:
l = LIST_ELEM(ctx->obj2, struct listener *, by_fe);
guid = &l->guid;
break;
case STAT_PX_ST_SV:
guid = &__objt_server(ctx->obj2)->guid;
break;
default:
ABORT_NOW();
return 1;
}
/* Skip objects without GUID. */
if (!guid->node.key)
return 1;
chunk_appendf(out, "%s,", (char *)guid->node.key);
for (i = 0; i < stats_count; ++i) {
/* Empty field for stats-file is used to skip its output,
* including any separator.
*/
if (field_format(line, i) == FF_EMPTY)
continue;
if (!stats_emit_raw_data_field(out, &line[i]))
return 0;
if (!chunk_strcat(out, ","))
return 0;
}
chunk_strcat(out, "\n");
return 1;
}
void stats_dump_file_header(int type, struct buffer *out)
{
const struct stat_col *col;
int i;
/* Caller must specified ither FE or BE. */
BUG_ON(!(type & ((1 << STATS_TYPE_FE) | (1 << STATS_TYPE_BE))));
if (type & (1 << STATS_TYPE_FE)) {
chunk_strcat(out, "#fe guid,");
for (i = 0; i < ST_I_PX_MAX; ++i) {
col = &stat_cols_px[i];
if (stcol_is_generic(col) &&
col->cap & (STATS_PX_CAP_FE|STATS_PX_CAP_LI)) {
chunk_appendf(out, "%s,", col->name);
}
}
}
else {
chunk_appendf(out, "#be guid,");
for (i = 0; i < ST_I_PX_MAX; ++i) {
col = &stat_cols_px[i];
if (stcol_is_generic(col) &&
col->cap & (STATS_PX_CAP_BE|STATS_PX_CAP_SRV)) {
chunk_appendf(out, "%s,", col->name);
}
}
}
chunk_strcat(out, "\n");
}
/* Parse an identified header line <header> starting with '#' character.
*
* If the section is recognized, <domain> will point to the current stats-file
* scope. <cols> will be filled as a matrix to identify each stat_col position
* using <st_tree> as prefilled proxy stats columns. If stats-file section is
* unknown, only <domain> will be set to STFILE_DOMAIN_UNSET.
*
* Returns 0 on success. On fatal error, non-zero is returned and parsing should
* be interrupted.
*/
static int parse_header_line(struct ist header, struct eb_root *st_tree,
enum stfile_domain *domain,
const struct stat_col *cols[])
{
enum stfile_domain dom = STFILE_DOMAIN_UNSET;
struct ist token;
char last;
int i;
header = iststrip(header);
last = istptr(header)[istlen(header) - 1];
token = istsplit(&header, ' ');
/* A header line is considered valid if:
* - a space delimiter is found and first token is several chars
* - last line character must be a comma separator
*/
if (!istlen(header) || istlen(token) == 1 || last != ',')
goto err;
if (isteq(token, ist("#fe")))
dom = STFILE_DOMAIN_PX_FE;
else if (isteq(token, ist("#be")))
dom = STFILE_DOMAIN_PX_BE;
/* Remove 'guid' field. */
token = istsplit(&header, ',');
if (!isteq(token, ist("guid"))) {
/* Fatal error if FE/BE domain without guid token. */
if (dom == STFILE_DOMAIN_PX_FE || dom == STFILE_DOMAIN_PX_BE)
goto err;
}
/* Unknown domain. Following lines should be ignored until next header. */
if (dom == STFILE_DOMAIN_UNSET)
return 0;
/* Generate matrix of stats column into cols[]. */
memset(cols, 0, sizeof(void *) * STAT_FILE_MAX_COL_COUNT);
i = 0;
while (istlen(header) && i < STAT_FILE_MAX_COL_COUNT) {
struct stcol_node *col_node;
const struct stat_col *col;
struct ebmb_node *node;
/* Lookup column by its name into <st_tree>. */
token = istsplit(&header, ',');
node = ebst_lookup(st_tree, ist0(token));
if (!node) {
++i;
continue;
}
col_node = ebmb_entry(node, struct stcol_node, name);
col = col_node->col;
/* Ignore column if its cap is not valid with current stats-file section. */
if ((dom == STFILE_DOMAIN_PX_FE &&
!(col->cap & (STATS_PX_CAP_FE|STATS_PX_CAP_LI))) ||
(dom == STFILE_DOMAIN_PX_BE &&
!(col->cap & (STATS_PX_CAP_BE|STATS_PX_CAP_SRV)))) {
++i;
continue;
}
cols[i] = col;
++i;
}
*domain = dom;
return 0;
err:
*domain = STFILE_DOMAIN_UNSET;
return 1;
}
/* Preload an individual counter instance stored at <counter> with <token>
* value> for the <col> stat column.
*
* Returns 0 on success else non-zero if counter was not updated.
*/
static int load_ctr(const struct stat_col *col, const struct ist token,
void* counter)
{
const enum field_nature fn = stcol_nature(col);
const enum field_format ff = stcol_format(col);
const char *ptr = istptr(token);
struct field value;
switch (ff) {
case FF_U64:
value.u.u64 = read_uint64(&ptr, istend(token));
break;
case FF_S32:
case FF_U32:
value.u.u32 = read_uint(&ptr, istend(token));
break;
default:
/* Unsupported field nature. */
return 1;
}
/* Do not load value if non numeric characters present. */
if (ptr != istend(token))
return 1;
if (fn == FN_COUNTER && ff == FF_U64) {
*(uint64_t *)counter = value.u.u64;
}
else if (fn == FN_RATE && ff == FF_U32) {
preload_freq_ctr(counter, value.u.u32);
}
else if (fn == FN_AGE && (ff == FF_U32 || ff == FF_S32)) {
*(uint32_t *)counter = ns_to_sec(now_ns) - value.u.u32;
}
else {
/* Unsupported field format/nature combination. */
return 1;
}
return 0;
}
/* Parse a non header stats-file line <line>. Specify current parsing <domain>
* and <cols> stats column matrix derived from the last header line.
*
* Returns 0 on success else non-zero.
*/
static int parse_stat_line(struct ist line,
enum stfile_domain domain,
const struct stat_col *cols[])
{
struct guid_node *node;
struct listener *li;
struct server *srv;
struct proxy *px;
struct ist token;
char *base_off, *base_off_shared;
char *guid;
int i, off;
token = istsplit(&line, ',');
guid = ist0(token);
if (!guid_is_valid_fmt(guid, NULL))
goto err;
node = guid_lookup(guid);
if (!node) {
/* Silently ignored unknown GUID. */
return 0;
}
switch (obj_type(node->obj_type)) {
case OBJ_TYPE_PROXY:
px = __objt_proxy(node->obj_type);
if (domain == STFILE_DOMAIN_PX_FE) {
if (!(px->cap & PR_CAP_FE))
return 0; /* silently ignored fe/be mismatch */
base_off_shared = (char *)px->fe_counters.shared.tg[0];
base_off = (char *)&px->fe_counters;
off = 0;
}
else if (domain == STFILE_DOMAIN_PX_BE) {
if (!(px->cap & PR_CAP_BE))
return 0; /* silently ignored fe/be mismatch */
base_off_shared = (char *)px->be_counters.shared.tg[0];
base_off = (char *)&px->be_counters;
off = 1;
}
else {
goto err;
}
break;
case OBJ_TYPE_LISTENER:
if (domain != STFILE_DOMAIN_PX_FE)
goto err;
li = __objt_listener(node->obj_type);
/* Listeners counters are not allocated if 'option socket-stats' unset. */
if (!li->counters)
return 0;
base_off_shared = (char *)li->counters->shared.tg[0];
base_off = (char *)li->counters;
off = 0;
break;
case OBJ_TYPE_SERVER:
if (domain != STFILE_DOMAIN_PX_BE)
goto err;
srv = __objt_server(node->obj_type);
base_off_shared = (char *)srv->counters.shared.tg[0];
base_off = (char *)&srv->counters;
off = 1;
break;
default:
goto err;
}
i = 0;
while (istlen(line) && i < STAT_FILE_MAX_COL_COUNT) {
const struct stat_col *col = cols[i++];
token = istsplit(&line, ',');
if (!istlen(token))
continue;
if (!col)
continue;
if (col->flags & STAT_COL_FL_SHARED)
load_ctr(col, token, base_off_shared + col->metric.offset[off]);
else
load_ctr(col, token, base_off + col->metric.offset[off]);
}
return 0;
err:
return 1;
}
/* Parse a stats-file and preload haproxy internal counters. */
void apply_stats_file(void)
{
const struct stat_col *cols[STAT_FILE_MAX_COL_COUNT];
struct eb_root st_tree = EB_ROOT;
enum stfile_domain domain;
int valid_format = 0;
FILE *file;
struct ist istline;
char *line = NULL;
int linenum;
if (!global.stats_file)
return;
file = fopen(global.stats_file, "r");
if (!file) {
ha_warning("config: Can't load stats-file '%s': cannot open file.\n", global.stats_file);
return;
}
/* Generate stat columns map indexed by name. */
if (generate_stat_tree(&st_tree, stat_cols_px)) {
ha_warning("config: Can't load stats-file '%s': not enough memory.\n", global.stats_file);
goto out;
}
line = malloc(sizeof(char) * LINESIZE);
if (!line) {
ha_warning("config: Can't load stats-file '%s': line alloc error.\n", global.stats_file);
goto out;
}
linenum = 0;
domain = STFILE_DOMAIN_UNSET;
while (1) {
if (!fgets(line, LINESIZE, file))
break;
++linenum;
istline = iststrip(ist(line));
if (!istlen(istline))
continue;
/* comment line starts by // */
if (istmatch(istline, ist("//")) != 0)
continue;
if (*istptr(istline) == '#') {
if (parse_header_line(istline, &st_tree, &domain, cols)) {
if (!valid_format) {
ha_warning("config: Invalid stats-file format in file '%s'.\n", global.stats_file);
break;
}
ha_warning("config: Ignored stats-file header line '%d' in file '%s'.\n", linenum, global.stats_file);
}
valid_format = 1;
}
else if (domain != STFILE_DOMAIN_UNSET) {
if (parse_stat_line(istline, domain, cols))
ha_warning("config: Ignored stats-file line %d in file '%s'.\n", linenum, global.stats_file);
}
else {
/* Stop parsing if first line is not a valid header.
* Allows to immediately stop reading garbage file.
*/
if (!valid_format) {
ha_warning("config: Invalid stats-file format in file '%s'.\n", global.stats_file);
break;
}
}
}
out:
while (!eb_is_empty(&st_tree)) {
struct ebmb_node *node = ebmb_first(&st_tree);
struct stcol_node *snode = ebmb_entry(node, struct stcol_node, name);
ebmb_delete(node);
ha_free(&snode);
}
ha_free(&line);
fclose(file);
}