Re: (ITS#3851) Berkeley DB Scalability Patch

[jongchoi@watson.ibm.com]

Quanah,

Here are more performance evaluation results of the Berkeley DB 
scalability patch. My results revealed no sign of performance 
degradation as reported in your result and I couldn't find any good 
reason why you had have such a devastation.

Here they go:

====================================================================================

SUT: IBM eServer x445 with 8 cpu (only 4 cpus were used for this experiment)

BDB Cache size: 1.6GB
OpenLDAP caches are set to minimum to observe the BDB cache effect only
(both entry cache and idl cache were set to 100 in size)

indexing: equality indexing on uid

====================================================================================

Performance under no memory pressure
(DirectoryMark messging scenario with a 512k entry DIT)

------------------------------------------------------------------------------------

With the Scalability Patch

population: 4m18.856s

warming up: 54.442s (search all entries locally)

messaging search (remote) from 8 clients for 5 mins: 11442 ops/sec

messaging search (remote) + 2 ldapadds (remote): search: 6293 ops/sec; 
add: 657.43 ops/sec

-----------------------------------------------------------------------------------

Without the Scalability Patch

population: 4m18.317s

warming up: 52.361s (search all entries locally)

messaging search (remote) from 8 clients for 5 mins: 11632 ops/sec

messaging search (remote) + 2 ldapadds (remote): search: 6416 ops/sec; 
add: 655.16 ops/sec

====================================================================================

Performance under memory pressure
(DirectoryMark messaging scenario with a 4m entry DIT)

------------------------------------------------------------------------------------

With the Scalability Patch

population: 38m23.576s

warming up: 13m30.087s (search all entries locally)

messaging search (remote) from 8 clients for 5 mins: 5420 ops/sec

messaging search (remote) + 2 ldapadds (remote): search: 4421 ops/sec; 
add: 342.63 ops/sec

-----------------------------------------------------------------------------------

Without the Scalability Patch

population: 77m14.390s

warming up: 85m55.154s (search all entries locally)

messaging search (remote) from 8 clients for 5 mins:  268 ops/sec

messaging search (remote) + 2 ldapadds (remote): search:  166 ops/sec; 
add:  18.97 ops/sec

====================================================================================

As you can see in the above results, virtually no performance 
degradation was observed in the no memory pressure condition. With 
memory pressure, it is shown that the Berkeley DB scalability patch 
significantly improves the scalability of both pure searches and mixed 
operations (searches and adds).

- Jong-Hyuk


quanah@symas.com wrote:

>Hi Jong,
>
>I took a look at the other effects this patch has, i.e., what happens when 
>you put OpenLDAP in a mixed RW situation with a version of BDB compiled 
>with your patches in place.  The results are devastating.
>
>Without the patch, using a 29% Write, 71% Read scenario:
>
>630.304 operations/second
>182.671 modifies/second
>447.632 searches/second
>
>
>With the patch, using a 29% Write, 71% Read scenario:
>
>53.707 operations/second
>15.554 modifies/second
>38.153 searches/second
>
>
>As you can see, the performance is more than 10 times worse with the patch 
>in place than without it.
>
>This was using the OpenLDAP 2.3.4 release on a 2 CPU SunFire v210 with 2 GB 
>of RAM, running Solaris 8.
>
>--Quanah
>
>--
>Quanah Gibson-Mount
>Product Engineer
>Symas Corporation
>Packaged, certified, and supported LDAP solutions powered by OpenLDAP:
><http://www.symas.com>
>
>
>
>
>
>  
>