Re: (ITS#8875) [Patch] Performance problems in back-mdb with large DITs and many aliases

[hyc]

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h...@symas.com wrote:
> The tool to generate the test LDIF is attached. It reads an LDIF containing 
> 500,000 users on stdin, and outputs the same LDIF,
> with aliases interspersed, on stdout.
> 
Slightly tweaked, creates the alias after the target entry. In case the server 
does referential integrity on loading.

-- 
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#define NUMUSERS 500000
#define NUMALIASES      30000
#define NUMSUBALIASES   435
#define SUFFIX  "dc=example,dc=com"

static const char ou1[] = "\
dn: ou=alias1," SUFFIX "\n\
objectclass: top\n\
objectclass: organizationalUnit\n\
ou: alias1\n";

static const char ou2[] = "\
dn: ou=alias2," SUFFIX "\n\
objectclass: top\n\
objectclass: organizationalUnit\n\
ou: alias2\n";

int qcmp(const void *a, const void *b)
{
        const int *i = a, *j = b;
        return *i - *j;
}

int main() {
        char line[1024], dn[1024], *ou;
        int aliases[NUMALIASES];
        int subaliases[NUMSUBALIASES];
        int i;
        int nusers=0, naliases=0, nsubaliases=0, showalias=0;
        
        /* select a random subset of users to generate aliases */
        srand(time(0L));
        for (i=0; i<NUMALIASES; i++) {
                aliases[i] = rand() % NUMUSERS;
        }
uniq1:
        qsort(aliases, NUMALIASES, sizeof(int), qcmp);
        /* make sure they're unique */
        for (i=1; i<NUMALIASES; i++) {
                if (aliases[i-1] == aliases[i]) {
                        aliases[i] = rand() % NUMUSERS;
                        goto uniq1;
                }
        }
        /* select a random susbset of aliases for the target subtree */
        for (i=0; i<NUMSUBALIASES; i++) {
                subaliases[i] = rand() % NUMALIASES;
        }
uniq2:
        qsort(subaliases, NUMSUBALIASES, sizeof(int), qcmp);
        /* make sure they're unique */
        for (i=1; i<NUMSUBALIASES; i++) {
                if (subaliases[i-1] == subaliases[i]) {
                        subaliases[i] = rand() % NUMALIASES;
                        goto uniq2;
                }
        }
        for (i=0; i<NUMSUBALIASES; i++) {
                subaliases[i] = aliases[subaliases[i]];
        }

        /* read LDIF */
        while (fgets(line, sizeof(line), stdin) != NULL) {
                if (line[0] == '#')
                        continue;
                if (!strncmp(line, "dn: ", 4)) {
                        /* we assume all users' DNs use uid for RDN */
                        if (!strncmp(line+4, "uid=", 4)) {
                                if (!nusers) {
                                        puts(ou1);
                                        puts(ou2);
                                }
                                if (showalias) {
                                        printf("dn: uid=x.%d,ou=%s," SUFFIX 
"\n", nusers, ou);
                                        puts("objectclass: alias");
                                        puts("objectclass: extensibleObject");
                                        printf("aliasedObjectName: %s\n", dn);
                                        showalias = 0;
                                }
                                if (nusers == aliases[naliases] ||
                                        nusers == subaliases[nsubaliases]) {
                                        if (nusers == subaliases[nsubaliases]) {
                                                ou = "alias2";
                                                nsubaliases++;
                                        } else {
                                                ou = "alias1";
                                        }
                                        naliases++;
                                        strcpy(dn, line+4);
                                        showalias = 1;
                                }
                                nusers++;
                        }
                }
                fputs(line, stdout);
        }
        return 0;
}

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