At Tue, 26 Jan 2021 11:43:21 +0200, Heikki Linnakangas <hlinn...@iki.fi> wrote
in
> Hi,
>
> On 19/11/2020 07:25, Kyotaro Horiguchi wrote:
> > Performance measurement on the attached showed better result about
> > searching but maybe worse for cache entry creation. Each time number
> > is the mean of 10 runs.
> > # Cacache (negative) entry creation
> > : time(ms) (% to master)
> > master : 3965.61 (100.0)
> > patched-off: 4040.93 (101.9)
> > patched-on : 4032.22 (101.7)
> > # Searching negative cache entries
> > master : 8173.46 (100.0)
> > patched-off: 7983.43 ( 97.7)
> > patched-on : 8049.88 ( 98.5)
> > # Creation, searching and expiration
> > master : 6393.23 (100.0)
> > patched-off: 6527.94 (102.1)
> > patched-on : 15880.01 (248.4)
> > That is, catcache searching gets faster by 2-3% but creation gets
> > slower by about 2%. If I moved the condition of 2 further up to
> > CatalogCacheCreateEntry(), that degradation reduced to 0.6%.
> > # Cacache (negative) entry creation
> > master : 3967.45 (100.0)
> > patched-off : 3990.43 (100.6)
> > patched-on : 4108.96 (103.6)
> > # Searching negative cache entries
> > master : 8106.53 (100.0)
> > patched-off : 8036.61 ( 99.1)
> > patched-on : 8058.18 ( 99.4)
> > # Creation, searching and expiration
> > master : 6395.00 (100.0)
> > patched-off : 6416.57 (100.3)
> > patched-on : 15830.91 (247.6)
>
> Can you share the exact script or steps to reproduce these numbers? I
> presume these are from the catcachebench extension, but I can't figure
> out which scenario above corresponds to which catcachebench
> test. Also, catcachebench seems to depend on a bunch of tables being
> created in schema called "test"; what tables did you use for the above
> numbers?
gen_tbl.pl to generate the tables, then run2.sh to run the
benchmark. sumlog.pl to summarize the result of run2.sh.
$ ./gen_tbl.pl | psql postgres
$ ./run2.sh | tee rawresult.txt | ./sumlog.pl
(I found a bug in a benchmark-aid function
(CatalogCacheFlushCatalog2), I repost an updated version soon.)
Simple explanation follows since the scripts are a kind of crappy..
run2.sh:
LOOPS : # of execution of catcachebench() in a single run
USES : Take the average of this number of fastest executions in a
single run.
BINROOT : Common parent directory of target binaries.
DATADIR : Data directory. (shared by all binaries)
PREC : FP format for time and percentage in a result.
TESTS : comma-separated numbers given to catcachebench.
The "run" function spec
run "binary-label" <binary-path> <A> <B> <C>
where A, B and C are the value for catalog_cache_prune_min_age. ""
means no setting (used for master binary). Currently only C is in
effect but all the three should be non-empty string to make it
effective.
The result output is:
test | version | n | r | stddev
------+-------------+-----+----------+---------
1 | patched-off | 1/3 | 14211.96 | 261.19
test : # of catcachebench(#)
version: binary label given to the run function
n : USES / LOOPS
r : result average time of catcachebench() in milliseconds
stddev : stddev of
regards.
--
Kyotaro Horiguchi
NTT Open Source Software Center
#! /usr/bin/perl
$collist = "";
foreach $i (0..1000) {
$collist .= sprintf(", c%05d int", $i);
}
$collist = substr($collist, 2);
printf "drop schema if exists test cascade;\n";
printf "create schema test;\n";
foreach $i (0..2999) {
printf "create table test.t%04d ($collist);\n", $i;
}
#!/bin/bash
LOOPS=3
USES=1
TESTS=1,2,3
BINROOT=/home/horiguti/bin
DATADIR=/home/horiguti/data/data_work
PREC="numeric(10,2)"
/usr/bin/killall postgres
/usr/bin/sleep 3
run() {
local BINARY=$1
local PGCTL=$2/bin/pg_ctl
local PGSQL=$2/bin/postgres
local PSQL=$2/bin/psql
if [ "$3" != "" ]; then
local SETTING1="set catalog_cache_prune_min_age to \"$3\";"
local SETTING2="set catalog_cache_prune_min_age to \"$4\";"
local SETTING3="set catalog_cache_prune_min_age to \"$5\";"
fi
# ($PGSQL -D $DATADIR 2>&1 > /dev/null)&
($PGSQL -D $DATADIR 2>&1 > /dev/null | /usr/bin/sed -e 's/^/# /')&
/usr/bin/sleep 3
${PSQL} postgres <<EOF
create extension if not exists catcachebench;
select catcachebench(0);
$SETTING3
select distinct * from unnest(ARRAY[${TESTS}]) as test,
LATERAL
(select '${BINARY}' as version,
'${USES}/' || (count(r) OVER())::text as n,
(avg(r) OVER ())::${PREC},
(stddev(r) OVER ())::${PREC}
from (select catcachebench(test) as r
from generate_series(1, ${LOOPS})) r
order by r limit ${USES}) r
EOF
$PGCTL --pgdata=$DATADIR stop 2>&1 > /dev/null | /usr/bin/sed -e 's/^/#
/'
# oreport > $BINARY_perf.txt
}
for i in $(seq 0 2); do
run "patched-off" $BINROOT/pgsql_catexp "-1" "-1" "-1"
run "patched-on" $BINROOT/pgsql_catexp "0" "0" "0"
run "master" $BINROOT/pgsql_master_o2 "" "" ""
done
#! /usr/bin/perl
while (<STDIN>) {
# if
(/^\s+([0-9])\s*\|\s*(\w+)\s*\|\s*(\S+)\s*\|\s*([\d.]+)\s*\|\s*(\w+)\s*$/) {
if
(/^\s+([0-9])\s*\|\s*(\S+)\s*\|\s*(\S+)\s*\|\s*([\d.]+)\s*\|\s*([\d.]+)\s*$/) {
$test = $1;
$bin = $2;
$time = $4;
if (defined $sum{$test}{$bin}) {
$sum{$test}{$bin} += $time;
$num{$test}{$bin}++;
} else {
$sum{$test}{$bin} = 0;
$num{$test}{$bin} = 0;
}
}
}
foreach $t (sort {$a cmp $b} keys %sum) {
$master{$t} = $sum{$t}{master} / $num{$t}{master};
}
foreach $t (sort {$a cmp $b} keys %sum) {
foreach $b (sort {$a cmp $b} keys %{$sum{$t}}) {
$mean = $sum{$t}{$b} / $num{$t}{$b};
$ratio = 100.0 * $mean / $master{$t};
printf("%-13s : %8.2f (%5.1f) (%d)\n", "$t:$b", $mean,
$ratio, $num{$t}{$b});
}
}
diff --git a/contrib/catcachebench/Makefile b/contrib/catcachebench/Makefile
new file mode 100644
index 0000000000..0478818b25
--- /dev/null
+++ b/contrib/catcachebench/Makefile
@@ -0,0 +1,17 @@
+MODULE_big = catcachebench
+OBJS = catcachebench.o
+
+EXTENSION = catcachebench
+DATA = catcachebench--0.0.sql
+PGFILEDESC = "catcachebench - benchmark for catcache pruning feature"
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/catcachebench
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/contrib/catcachebench/catcachebench--0.0.sql b/contrib/catcachebench/catcachebench--0.0.sql
new file mode 100644
index 0000000000..ea9cd62abb
--- /dev/null
+++ b/contrib/catcachebench/catcachebench--0.0.sql
@@ -0,0 +1,14 @@
+/* contrib/catcachebench/catcachebench--0.0.sql */
+
+-- complain if script is sourced in psql, rather than via CREATE EXTENSION
+\echo Use "CREATE EXTENSION catcachebench" to load this file. \quit
+
+CREATE FUNCTION catcachebench(IN type int)
+RETURNS double precision
+AS 'MODULE_PATHNAME', 'catcachebench'
+LANGUAGE C STRICT VOLATILE;
+
+CREATE FUNCTION catcachereadstats(OUT catid int, OUT reloid oid, OUT searches bigint, OUT hits bigint, OUT neg_hits bigint)
+RETURNS SETOF record
+AS 'MODULE_PATHNAME', 'catcachereadstats'
+LANGUAGE C STRICT VOLATILE;
diff --git a/contrib/catcachebench/catcachebench.c b/contrib/catcachebench/catcachebench.c
new file mode 100644
index 0000000000..f93d60e721
--- /dev/null
+++ b/contrib/catcachebench/catcachebench.c
@@ -0,0 +1,338 @@
+/*
+ * catcachebench: test code for cache pruning feature
+ */
+/* #define CATCACHE_STATS */
+#include "postgres.h"
+#include "catalog/pg_type.h"
+#include "catalog/pg_statistic.h"
+#include "executor/spi.h"
+#include "funcapi.h"
+#include "libpq/pqsignal.h"
+#include "utils/catcache.h"
+#include "utils/syscache.h"
+#include "utils/timestamp.h"
+
+Oid tableoids[10000];
+int ntables = 0;
+int16 attnums[1000];
+int natts = 0;
+
+PG_MODULE_MAGIC;
+
+double catcachebench1(void);
+double catcachebench2(void);
+double catcachebench3(void);
+void collectinfo(void);
+void catcachewarmup(void);
+
+PG_FUNCTION_INFO_V1(catcachebench);
+PG_FUNCTION_INFO_V1(catcachereadstats);
+
+extern void CatalogCacheFlushCatalog2(Oid catId);
+extern int64 catcache_called;
+extern CatCache *SysCache[];
+
+typedef struct catcachestatsstate
+{
+ TupleDesc tupd;
+ int catId;
+} catcachestatsstate;
+
+Datum
+catcachereadstats(PG_FUNCTION_ARGS)
+{
+ catcachestatsstate *state_data = NULL;
+ FuncCallContext *fctx;
+
+ if (SRF_IS_FIRSTCALL())
+ {
+ TupleDesc tupdesc;
+ MemoryContext mctx;
+
+ fctx = SRF_FIRSTCALL_INIT();
+ mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+ state_data = palloc(sizeof(catcachestatsstate));
+
+ /* Build a tuple descriptor for our result type */
+ if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
+ elog(ERROR, "return type must be a row type");
+
+ state_data->tupd = tupdesc;
+ state_data->catId = 0;
+
+ fctx->user_fctx = state_data;
+
+ MemoryContextSwitchTo(mctx);
+ }
+
+ fctx = SRF_PERCALL_SETUP();
+ state_data = fctx->user_fctx;
+
+ if (state_data->catId < SysCacheSize)
+ {
+ Datum values[5];
+ bool nulls[5];
+ HeapTuple resulttup;
+ Datum result;
+ int catId = state_data->catId++;
+
+ memset(nulls, 0, sizeof(nulls));
+ memset(values, 0, sizeof(values));
+ values[0] = Int16GetDatum(catId);
+ values[1] = ObjectIdGetDatum(SysCache[catId]->cc_reloid);
+#ifdef CATCACHE_STATS
+ values[2] = Int64GetDatum(SysCache[catId]->cc_searches);
+ values[3] = Int64GetDatum(SysCache[catId]->cc_hits);
+ values[4] = Int64GetDatum(SysCache[catId]->cc_neg_hits);
+#endif
+ resulttup = heap_form_tuple(state_data->tupd, values, nulls);
+ result = HeapTupleGetDatum(resulttup);
+
+ SRF_RETURN_NEXT(fctx, result);
+ }
+
+ SRF_RETURN_DONE(fctx);
+}
+
+Datum
+catcachebench(PG_FUNCTION_ARGS)
+{
+ int testtype = PG_GETARG_INT32(0);
+ double ms;
+
+ collectinfo();
+
+ /* flush the catalog -- safe? don't mind. */
+ CatalogCacheFlushCatalog2(StatisticRelationId);
+
+ switch (testtype)
+ {
+ case 0:
+ catcachewarmup(); /* prewarm of syscatalog */
+ PG_RETURN_NULL();
+ case 1:
+ ms = catcachebench1(); break;
+ case 2:
+ ms = catcachebench2(); break;
+ case 3:
+ ms = catcachebench3(); break;
+ default:
+ elog(ERROR, "Invalid test type: %d", testtype);
+ }
+
+ PG_RETURN_DATUM(Float8GetDatum(ms));
+}
+
+/*
+ * fetch all attribute entires of all tables.
+ */
+double
+catcachebench1(void)
+{
+ int t, a;
+ instr_time start,
+ duration;
+
+ PG_SETMASK(&BlockSig);
+ INSTR_TIME_SET_CURRENT(start);
+ for (t = 0 ; t < ntables ; t++)
+ {
+ for (a = 0 ; a < natts ; a++)
+ {
+ HeapTuple tup;
+
+ tup = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(tableoids[t]),
+ Int16GetDatum(attnums[a]),
+ BoolGetDatum(false));
+ /* should be null, but.. */
+ if (HeapTupleIsValid(tup))
+ ReleaseSysCache(tup);
+ }
+ }
+ INSTR_TIME_SET_CURRENT(duration);
+ INSTR_TIME_SUBTRACT(duration, start);
+ PG_SETMASK(&UnBlockSig);
+
+ return INSTR_TIME_GET_MILLISEC(duration);
+};
+
+/*
+ * fetch all attribute entires of a table 6000 times.
+ */
+double
+catcachebench2(void)
+{
+ int t, a;
+ instr_time start,
+ duration;
+
+ PG_SETMASK(&BlockSig);
+ INSTR_TIME_SET_CURRENT(start);
+ for (t = 0 ; t < 240000 ; t++)
+ {
+ for (a = 0 ; a < natts ; a++)
+ {
+ HeapTuple tup;
+
+ tup = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(tableoids[0]),
+ Int16GetDatum(attnums[a]),
+ BoolGetDatum(false));
+ /* should be null, but.. */
+ if (HeapTupleIsValid(tup))
+ ReleaseSysCache(tup);
+ }
+ }
+ INSTR_TIME_SET_CURRENT(duration);
+ INSTR_TIME_SUBTRACT(duration, start);
+ PG_SETMASK(&UnBlockSig);
+
+ return INSTR_TIME_GET_MILLISEC(duration);
+};
+
+/* SetCatCacheClock - set catcache timestamp source clock */
+uint64 catcacheclock;
+static inline void
+SetCatCacheClock(TimestampTz ts)
+{
+ catcacheclock = (uint64) ts;
+}
+
+/*
+ * fetch all attribute entires of all tables twice with having expiration
+ * happen.
+ */
+double
+catcachebench3(void)
+{
+ const int clock_step = 1000;
+ int i, t, a;
+ instr_time start,
+ duration;
+
+ PG_SETMASK(&BlockSig);
+ INSTR_TIME_SET_CURRENT(start);
+ for (i = 0 ; i < 4 ; i++)
+ {
+ int ct = clock_step;
+
+ for (t = 0 ; t < ntables ; t++)
+ {
+ /*
+ * catcacheclock is updated by transaction timestamp, so needs to
+ * be updated by other means for this test to work. Here I choosed
+ * to update the clock every 1000 tables scan.
+ */
+ if (--ct < 0)
+ {
+ SetCatCacheClock(GetCurrentTimestamp());
+ ct = clock_step;
+ }
+ for (a = 0 ; a < natts ; a++)
+ {
+ HeapTuple tup;
+
+ tup = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(tableoids[t]),
+ Int16GetDatum(attnums[a]),
+ BoolGetDatum(false));
+ /* should be null, but.. */
+ if (HeapTupleIsValid(tup))
+ ReleaseSysCache(tup);
+ }
+ }
+ }
+ INSTR_TIME_SET_CURRENT(duration);
+ INSTR_TIME_SUBTRACT(duration, start);
+ PG_SETMASK(&UnBlockSig);
+
+ return INSTR_TIME_GET_MILLISEC(duration);
+};
+
+void
+catcachewarmup(void)
+{
+ int t, a;
+
+ /* load up catalog tables */
+ for (t = 0 ; t < ntables ; t++)
+ {
+ for (a = 0 ; a < natts ; a++)
+ {
+ HeapTuple tup;
+
+ tup = SearchSysCache3(STATRELATTINH,
+ ObjectIdGetDatum(tableoids[t]),
+ Int16GetDatum(attnums[a]),
+ BoolGetDatum(false));
+ /* should be null, but.. */
+ if (HeapTupleIsValid(tup))
+ ReleaseSysCache(tup);
+ }
+ }
+}
+
+void
+collectinfo(void)
+{
+ int ret;
+ Datum values[10000];
+ bool nulls[10000];
+ Oid types0[] = {OIDOID};
+ int i;
+
+ ntables = 0;
+ natts = 0;
+
+ SPI_connect();
+ /* collect target tables */
+ ret = SPI_execute("select oid from pg_class where relnamespace = (select oid from pg_namespace where nspname = \'test\')",
+ true, 0);
+ if (ret != SPI_OK_SELECT)
+ elog(ERROR, "Failed 1");
+ if (SPI_processed == 0)
+ elog(ERROR, "no relation found in schema \"test\"");
+ if (SPI_processed > 10000)
+ elog(ERROR, "too many relation found in schema \"test\"");
+
+ for (i = 0 ; i < SPI_processed ; i++)
+ {
+ heap_deform_tuple(SPI_tuptable->vals[i], SPI_tuptable->tupdesc,
+ values, nulls);
+ if (nulls[0])
+ elog(ERROR, "Failed 2");
+
+ tableoids[ntables++] = DatumGetObjectId(values[0]);
+ }
+ SPI_finish();
+ elog(DEBUG1, "%d tables found", ntables);
+
+ values[0] = ObjectIdGetDatum(tableoids[0]);
+ nulls[0] = false;
+ SPI_connect();
+ ret = SPI_execute_with_args("select attnum from pg_attribute where attrelid = (select oid from pg_class where oid = $1)",
+ 1, types0, values, NULL, true, 0);
+ if (SPI_processed == 0)
+ elog(ERROR, "no attribute found in table %d", tableoids[0]);
+ if (SPI_processed > 10000)
+ elog(ERROR, "too many relation found in table %d", tableoids[0]);
+
+ /* collect target attributes. assuming all tables have the same attnums */
+ for (i = 0 ; i < SPI_processed ; i++)
+ {
+ int16 attnum;
+
+ heap_deform_tuple(SPI_tuptable->vals[i], SPI_tuptable->tupdesc,
+ values, nulls);
+ if (nulls[0])
+ elog(ERROR, "Failed 3");
+ attnum = DatumGetInt16(values[0]);
+
+ if (attnum > 0)
+ attnums[natts++] = attnum;
+ }
+ SPI_finish();
+ elog(DEBUG1, "%d attributes found", natts);
+}
diff --git a/contrib/catcachebench/catcachebench.control b/contrib/catcachebench/catcachebench.control
new file mode 100644
index 0000000000..3fc9d2e420
--- /dev/null
+++ b/contrib/catcachebench/catcachebench.control
@@ -0,0 +1,6 @@
+# catcachebench
+
+comment = 'benchmark for catcache pruning'
+default_version = '0.0'
+module_pathname = '$libdir/catcachebench'
+relocatable = true
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index fa2b49c676..11b94504af 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -740,6 +740,41 @@ CatalogCacheFlushCatalog(Oid catId)
CACHE_elog(DEBUG2, "end of CatalogCacheFlushCatalog call");
}
+
+/* FUNCTION FOR BENCHMARKING */
+void
+CatalogCacheFlushCatalog2(Oid catId)
+{
+ slist_iter iter;
+
+ CACHE_elog(DEBUG2, "CatalogCacheFlushCatalog called for %u", catId);
+
+ slist_foreach(iter, &CacheHdr->ch_caches)
+ {
+ CatCache *cache = slist_container(CatCache, cc_next, iter.cur);
+
+ /* Does this cache store tuples of the target catalog? */
+ if (cache->cc_reloid == catId)
+ {
+ /* Yes, so flush all its contents */
+ ResetCatalogCache(cache);
+
+ /* Tell inval.c to call syscache callbacks for this cache */
+ CallSyscacheCallbacks(cache->id, 0);
+
+ cache->cc_nbuckets = 128;
+ pfree(cache->cc_bucket);
+ cache->cc_bucket =
+ (dlist_head *) MemoryContextAllocZero(CacheMemoryContext,
+ cache->cc_nbuckets * sizeof(dlist_head));
+ elog(LOG, "Catcache reset");
+ }
+ }
+
+ CACHE_elog(DEBUG2, "end of CatalogCacheFlushCatalog call");
+}
+/* END: FUNCTION FOR BENCHMARKING */
+
/*
* InitCatCache
*
diff --git a/src/backend/utils/cache/syscache.c b/src/backend/utils/cache/syscache.c
index e4dc4ee34e..b60416ec63 100644
--- a/src/backend/utils/cache/syscache.c
+++ b/src/backend/utils/cache/syscache.c
@@ -994,7 +994,7 @@ static const struct cachedesc cacheinfo[] = {
}
};
-static CatCache *SysCache[SysCacheSize];
+CatCache *SysCache[SysCacheSize];
static bool CacheInitialized = false;
