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| author | Keith Bostic <keith@wiredtiger.com> | 2012-03-21 19:25:15 +0000 |
|---|---|---|
| committer | Keith Bostic <keith@wiredtiger.com> | 2012-03-21 19:25:15 +0000 |
| commit | d346eade1ec34a6c09b95317138211cf966a945b (patch) | |
| tree | dc8ee2ca87b10a63104f32c4e507d23b9e64229b | |
| parent | 966b216ee8d9d8dab52b726e66673ffa71d861cb (diff) | |
| download | mongo-d346eade1ec34a6c09b95317138211cf966a945b.tar.gz | |
Add a section on replacing the default system memory allocator to the
tuning page.
An example setting the cache to 10MB isn't useful, crank the example
to 500MB.
| -rw-r--r-- | docs/src/spell.ok | 3 | ||||
| -rw-r--r-- | docs/src/tuning.dox | 14 | ||||
| -rw-r--r-- | examples/c/ex_config.c | 2 |
3 files changed, 16 insertions, 3 deletions
diff --git a/docs/src/spell.ok b/docs/src/spell.ok index dab1d9ade86..05071b53215 100644 --- a/docs/src/spell.ok +++ b/docs/src/spell.ok @@ -133,6 +133,7 @@ inuse io ip je +jemalloc jni json keyexist @@ -154,6 +155,7 @@ lsn lt mailto mainpage +malloc malloc'd marshalled marshalling @@ -255,6 +257,7 @@ subpage superset tablename tcl +tcmalloc td th thang diff --git a/docs/src/tuning.dox b/docs/src/tuning.dox index 71117cfdc29..e179e362bcc 100644 --- a/docs/src/tuning.dox +++ b/docs/src/tuning.dox @@ -9,7 +9,7 @@ function. The effectiveness of the cache can be measured by reviewing the page eviction statistics for the database. -An example of setting a cache size to 10MB: +An example of setting a cache size to 500MB: @snippet ex_config.c configure cache size @@ -90,6 +90,17 @@ An example of configuring page sizes: @snippet ex_file.c file create +@section memory Memory allocation + +I/O intensive threaded applications, where the working set does not fit +into the available cache, can be dominated by memory allocation because +the WiredTiger engine has to free and re-allocate memory as part of many +queries. Replacing the system's malloc implementation with one that has +better threaded performance (for example, Google's +<a href="http://goog-perftools.sourceforge.net/doc/tcmalloc.html">tcmalloc</a>, +or <a href="http://www.canonware.com/jemalloc">jemalloc</a>), +can dramatically improve throughput. + @section statistics Performance monitoring with statistics WiredTiger maintains a variety of statistics that can be read with a @@ -116,5 +127,4 @@ statistics until the cursor returns the end of the list. Note the raw value of the statistic is available from the \c value field, as well as a printable string version of the value. - */ diff --git a/examples/c/ex_config.c b/examples/c/ex_config.c index 2b7f8d5d09f..4f3d109abde 100644 --- a/examples/c/ex_config.c +++ b/examples/c/ex_config.c @@ -46,7 +46,7 @@ int main(void) /*! [configure cache size] */ if ((ret = wiredtiger_open(home, NULL, - "create,cache_size=10M", &conn)) != 0) + "create,cache_size=500M", &conn)) != 0) fprintf(stderr, "Error connecting to %s: %s\n", home, wiredtiger_strerror(ret)); /*! [configure cache size] */ |