Initial hot_backup

The idea being that a consistent inker manifest and set of journal files is guaranteed - with hard links to the actual manifest files.

test/end_to_end/recovery_SUITE.erl

@@ -2,7 +2,8 @@
 -include_lib("common_test/include/ct.hrl").
 -include("include/leveled.hrl").
 -export([all/0]).
--export([retain_strategy/1,
+-export([hot_backup_simple/1,
+            retain_strategy/1,
             recovr_strategy/1,
             aae_missingjournal/1,
             aae_bustedjournal/1,
@@ -10,6 +11,7 @@
             ]).
 
 all() -> [
+            hot_backup_simple,
             retain_strategy,
             recovr_strategy,
             aae_missingjournal,
@@ -17,6 +19,39 @@ all() -> [
             journal_compaction_bustedjournal
             ].
 
+
+hot_backup_simple(_Config) ->
+    % The journal may have a hot backup.  This allows for an online Bookie
+    % to be sent a message to prepare a backup function, which an asynchronous
+    % worker can then call to generate a backup taken at the point in time
+    % the original message was processsed.
+    %
+    % The basic test is to:
+    % 1 - load a Bookie, take a backup, delete the original path, restore from
+    % that path
+    RootPath = testutil:reset_filestructure(),
+    BookOpts = [{root_path, RootPath},
+                    {cache_size, 1000},
+                    {max_journalsize, 10000000},
+                    {sync_strategy, testutil:sync_strategy()}],
+    {ok, Spcl1, LastV1} = rotating_object_check(BookOpts, "Bucket1", 10000),
+    {ok, Book1} = leveled_bookie:book_start(BookOpts),
+    {async, BackupFun} = leveled_bookie:book_hotbackup(Book1),
+    BackupPath = testutil:reset_filestructure("backup0"),
+    ok = BackupFun(BackupPath),
+    ok = leveled_bookie:book_close(Book1),
+    RootPath = testutil:reset_filestructure(),
+    BookOptsBackup = [{root_path, BackupPath},
+                        {cache_size, 2000},
+                        {max_journalsize, 20000000},
+                        {sync_strategy, testutil:sync_strategy()}],
+    {ok, BookBackup} = leveled_bookie:book_start(BookOptsBackup),
+    ok = testutil:check_indexed_objects(BookBackup, "Bucket1", Spcl1, LastV1),
+    ok = leveled_bookie:book_close(BookBackup),
+    BackupPath = testutil:reset_filestructure("backup0").
+
+
+
 retain_strategy(_Config) ->
     RootPath = testutil:reset_filestructure(),
     BookOpts = [{root_path, RootPath},