chore: max_total_wal_size option

Author: luislhl

docs/api/options.rst

@@ -713,6 +713,21 @@ Options objects
         | *Type:* ``int``
         | *Default:* ``0``
 
+    .. py:attribute:: max_total_wal_size
+
+        Once write-ahead logs exceed this size, we will start forcing the flush of
+        column families whose memtables are backed by the oldest live WAL file
+        (i.e. the ones that are causing all the space amplification). If set to 0
+        (default), we will dynamically choose the WAL size limit to be
+        [sum of all write_buffer_size * max_write_buffer_number] * 4.
+        This option takes effect only when there are more than one column family as
+        otherwise the wal size is dictated by the write_buffer_size.
+
+        Dynamically changeable through SetDBOptions() API.
+
+        | *Type:* ``int``
+        | *Default:* ``0``
+
     .. py:attribute:: manifest_preallocation_size
 
         Number of bytes to preallocate (via fallocate) the manifest

rocksdb/_rocksdb.pyx

@@ -1229,6 +1229,12 @@ cdef class Options(ColumnFamilyOptions):
         def __set__(self, value):
             self.opts.WAL_size_limit_MB = value
 
+    property max_total_wal_size:
+        def __get__(self):
+            return self.opts.max_total_wal_size
+        def __set__(self, value):
+            self.opts.max_total_wal_size = value
+
     property manifest_preallocation_size:
         def __get__(self):
             return self.opts.manifest_preallocation_size

rocksdb/options.pxd

@@ -88,6 +88,7 @@ cdef extern from "rocksdb/options.h" namespace "rocksdb":
         int table_cache_numshardbits
         uint64_t WAL_ttl_seconds
         uint64_t WAL_size_limit_MB
+        uint64_t max_total_wal_size
         size_t manifest_preallocation_size
         cpp_bool allow_mmap_reads
         cpp_bool allow_mmap_writes