17127.78
18463.38

Table 5: Performance in relation to nsslapd-cachesize/nsslapd-cachememsize for various database sizes

Number of Entries

Searches per second with

Searches per second with

in the Database

cachememsize 100% or max,

cachememsize default,

 

cachesize -1,

cachesize 1,

 

dbcachesize 100% or max

dbcachesize 100% or max

100

19597.22

12049.68

10,000

19169.68

11314.75

100,000

18983.23

11399.68

250,000

18545.38

11056.25

500,000

18487.29

11048.27

1,000,000

18398.92

10817.41

From Table 5, you can see from the second column that if all the entries are cached in the entry cache (cachesize of -1, unlimited entries), and if all the pages are cached in the dbcache, then the search throughput changes minimally, no matter how big the database is. So, the number of database entries does not affect performance as long as all entries are cached. However, as shown from the third column, if only a very small percentage of entries can be held in cache (cachesize of 1), the search throughput for different sizes of databases also varies minimally. So, if dbcachesize is big enough to hold all the pages, then the average exact search throughput for any size of database with HPDS 8.1 will be between around 18398 to 19597 operations/second, depending on the number of entries present in the database (the size of the entry cache). If the cache size is restricted to minimize the number of entries in cache, the average search throughput drops considerably, ranging from around 10817 to 12049 operations/second.

Data collection 5: (Access log on compared to Access log off)

This set of data is collected to show how logging can affect the performance.

•Server: Montvale-based test configuration 8 CPUs @1.6GHz each

•Number of entries: 500K

•Number of client threads: 128

•HPDS parameter settings: nsslapd-dbcachesize and nsslapd-cachememsize are big enough to cache all the entries, and nsslapd-threadnumber is set to 6.

Table 6 shows that by turning the access log off, the exact search throughput can increase about 4% in a Montvale-based test bed.

Table 6: Performance in relation to nsslapd-accesslog setting: (on or off) Access log on or off Searches per second

ON

OFF

Data collection 6: (SSL connection enabled compared to SSL connection disabled)

This set of data is collected to show the performance impact if SSL connection is enabled or disabled.

•Server: Montvale-based test configuration 8 CPUs @1.6GHz each

•Number of entries: 500K

•Number of client threads: 128

•HPDS parameter settings: assume nsslapd-dbcachesize and nsslapd-cachememsize are big enough to cache all the entries. nsslapd-threadnumber is set to 6.

•Special setting in client: “Bind for every operation” option is selected.

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