TrieCache: Fine tune the size of the local and node cache

primitives/trie/src/cache/mod.rs

@@ -91,9 +91,13 @@ const LOCAL_NODE_CACHE_MAX_INLINE_SIZE: usize = 512 * 1024;
 const LOCAL_VALUE_CACHE_MAX_INLINE_SIZE: usize = 512 * 1024;
 
 /// The maximum size of the memory allocated on the heap by the local cache, in bytes.
-const LOCAL_NODE_CACHE_MAX_HEAP_SIZE: usize = 2 * 1024 * 1024;
+///
+/// The size of the node cache should always be bigger than the value cache. The value
+/// cache is only holding weak references to the actual values found in the nodes and
+/// we account for the size of the node as part of the node cache.
+const LOCAL_NODE_CACHE_MAX_HEAP_SIZE: usize = 8 * 1024 * 1024;
 /// Same as [`LOCAL_NODE_CACHE_MAX_HEAP_SIZE`].
-const LOCAL_VALUE_CACHE_MAX_HEAP_SIZE: usize = 4 * 1024 * 1024;
+const LOCAL_VALUE_CACHE_MAX_HEAP_SIZE: usize = 2 * 1024 * 1024;
 
 /// The size of the shared cache.
 #[derive(Debug, Clone, Copy)]