Disallow the cache_resident flag on LSM trees.

Refs WT-1905
wiredtiger · May 5, 2015 · 3cfca1a · 3cfca1a
1 parent f4aec90
commit 3cfca1a
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Showing 4 changed files with 13 additions and 6 deletions.
diff --git a/dist/api_data.py b/dist/api_data.py
@@ -142,8 +142,8 @@ def __cmp__(self, other):
         are also available.  See @ref compression for more information''',
         func='__wt_compressor_confchk'),
     Config('cache_resident', 'false', r'''
-        do not ever evict the object's pages; see @ref
-        tuning_cache_resident for more information''',
+        do not ever evict the object's pages from cache. Not compatible with
+        LSM tables; see @ref tuning_cache_resident for more information''',
         type='boolean'),
     Config('checksum', 'uncompressed', r'''
         configure block checksums; permitted values are <code>on</code>

diff --git a/src/docs/tune-cache.dox b/src/docs/tune-cache.dox
@@ -23,7 +23,8 @@ the page eviction statistics for the database.
 Objects can be created as cache resident - that is their contents will
 remain in cache and never be considered for the purposes of cache
 eviction. Cache residence can be configured with the WT_SESSION::create
-"cache_resident" configuration string.
+"cache_resident" configuration string. LSM tree objects do not support
+the "cache_resident" setting.
 
 Configuring a cache resident object has several effects:
 

diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
@@ -996,9 +996,10 @@ struct __wt_session {
 	 * builtin support for \c "bzip2"\, \c "snappy"\, \c "lz4" or \c "zlib"
 	 * compression\, these names are also available.  See @ref compression
 	 * for more information., a string; default \c none.}
-	 * @config{cache_resident, do not ever evict the object's pages; see
-	 * @ref tuning_cache_resident for more information., a boolean flag;
-	 * default \c false.}
+	 * @config{cache_resident, do not ever evict the object's pages from
+	 * cache.  Not compatible with LSM tables; see @ref
+	 * tuning_cache_resident for more information., a boolean flag; default
+	 * \c false.}
 	 * @config{checksum, configure block checksums; permitted values are
 	 * <code>on</code> (checksum all blocks)\, <code>off</code> (checksum no
 	 * blocks) and <code>uncompresssed</code> (checksum only blocks which

diff --git a/src/lsm/lsm_tree.c b/src/lsm/lsm_tree.c
@@ -348,6 +348,11 @@ __wt_lsm_tree_create(WT_SESSION_IMPL *session,
 	WT_ERR(__wt_strndup(
 	    session, cval.str, cval.len, &lsm_tree->collator_name));
 
+	WT_ERR(__wt_config_gets(session, cfg, "cache_resident", &cval));
+	if (cval.val != 0)
+		WT_ERR_MSG(session, EINVAL,
+		    "The cache_resident flag is not compatible with LSM");
+
 	WT_ERR(__wt_config_gets(session, cfg, "lsm.auto_throttle", &cval));
 	if (cval.val)
 		F_SET(lsm_tree, WT_LSM_TREE_THROTTLE);