Merge pull request #2556 from wiredtiger/wt-2451

(cherry picked from commit c4f9f62)

WT-2451 Allow eviction of WiredTiger metadata.

2 files changed, 62 insertions, 1 deletions

diff --git a/src/btree/bt_handle.c b/src/btree/bt_handle.c
index f9ddc7f2dd3..00452af549d 100644
--- a/src/btree/bt_handle.c
+++ b/src/btree/bt_handle.c
@@ -254,7 +254,11 @@ __btree_conf(WT_SESSION_IMPL *session, WT_CKPT *ckpt)
 
 	/* Eviction; the metadata file is never evicted. */
 	if (WT_IS_METADATA(btree->dhandle))
-		F_SET(btree, WT_BTREE_IN_MEMORY | WT_BTREE_NO_EVICTION);
+		/*
+		 * Special settings for metadata: skew eviction so metadata
+		 * almost always stays in cache
+		 */
+		btree->evict_priority = WT_EVICT_INT_SKEW;
 	else {
 		WT_RET(__wt_config_gets(session, cfg, "cache_resident", &cval));
 		if (cval.val)
diff --git a/test/suite/test_schema07.py b/test/suite/test_schema07.py
new file mode 100644
index 00000000000..67a46fb8cf0
--- /dev/null
+++ b/test/suite/test_schema07.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python
+#
+# Public Domain 2014-2016 MongoDB, Inc.
+# Public Domain 2008-2014 WiredTiger, Inc.
+#
+# This is free and unencumbered software released into the public domain.
+#
+# Anyone is free to copy, modify, publish, use, compile, sell, or
+# distribute this software, either in source code form or as a compiled
+# binary, for any purpose, commercial or non-commercial, and by any
+# means.
+#
+# In jurisdictions that recognize copyright laws, the author or authors
+# of this software dedicate any and all copyright interest in the
+# software to the public domain. We make this dedication for the benefit
+# of the public at large and to the detriment of our heirs and
+# successors. We intend this dedication to be an overt act of
+# relinquishment in perpetuity of all present and future rights to this
+# software under copyright law.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+# IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+
+import wiredtiger, wttest
+
+# test_schema07.py
+#    Test that long-running tests don't fill the cache with metadata
+class test_schema07(wttest.WiredTigerTestCase):
+    tablename = 'table:test_schema07'
+
+    def setUpConnectionOpen(self, dir):
+        wtopen_args = 'create,cache_size=10MB'
+        conn = wiredtiger.wiredtiger_open(dir, wtopen_args)
+        self.pr(`conn`)
+        return conn
+
+    @wttest.longtest("Creating many tables shouldn't fill the cache")
+    def test_many_tables(self):
+        s = self.session
+        # We have a 10MB cache, metadata is (well) over 512B per table,
+        # if we can create 20K tables, something must be cleaning up.
+        for i in xrange(20000):
+            uri = '%s-%06d' % (self.tablename, i)
+            s.create(uri)
+            c = s.open_cursor(uri)
+            # This will block if the metadata fills the cache
+            c["key"] = "value"
+            c.close()
+            self.session.drop(uri)
+
+if __name__ == '__main__':
+    wttest.run()