geo-rep: Fix History post process

This patch removes changelogsdb part of post processing since
not got much performance advantage as expected.

Entry stime and other logging improvements retained.

BUG: 1364420
Change-Id: Ib99d23f09d96c14bc28225b47d9134260f5551bf
Signed-off-by: Aravinda VK <avishwan@redhat.com>
Reviewed-on: http://review.gluster.org/15371
NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Smoke: Gluster Build System <jenkins@build.gluster.org>

5 files changed, 123 insertions, 320 deletions

diff --git a/geo-replication/syncdaemon/Makefile.am b/geo-replication/syncdaemon/Makefile.am
index 88c9e64e52..7cdaf45dde 100644
--- a/geo-replication/syncdaemon/Makefile.am
+++ b/geo-replication/syncdaemon/Makefile.am
@@ -3,6 +3,6 @@ syncdaemondir = $(libexecdir)/glusterfs/python/syncdaemon
 syncdaemon_PYTHON = gconf.py gsyncd.py __init__.py master.py README.md repce.py \
 	resource.py configinterface.py syncdutils.py monitor.py libcxattr.py \
 	$(top_builddir)/contrib/ipaddr-py/ipaddr.py libgfchangelog.py changelogagent.py \
-	gsyncdstatus.py changelogsdb.py conf.py
+	gsyncdstatus.py conf.py
 
 CLEANFILES =
diff --git a/geo-replication/syncdaemon/changelogsdb.py b/geo-replication/syncdaemon/changelogsdb.py
deleted file mode 100644
index 7e64158e7a..0000000000
--- a/geo-replication/syncdaemon/changelogsdb.py
+++ /dev/null
@@ -1,111 +0,0 @@
-#
-# Copyright (c) 2016 Red Hat, Inc. <http://www.redhat.com>
-# This file is part of GlusterFS.
-
-# This file is licensed to you under your choice of the GNU Lesser
-# General Public License, version 3 or any later version (LGPLv3 or
-# later), or the GNU General Public License, version 2 (GPLv2), in all
-# cases as published by the Free Software Foundation.
-#
-
-import os
-import sqlite3
-from errno import ENOENT
-
-conn = None
-cursor = None
-
-
-def db_commit():
-    conn.commit()
-
-
-def db_init(db_path):
-    global conn, cursor
-    # Remove Temp Db
-    try:
-        os.unlink(db_path)
-        os.unlink(db_path + "-journal")
-    except OSError as e:
-        if e.errno != ENOENT:
-            raise
-
-    conn = sqlite3.connect(db_path)
-    cursor = conn.cursor()
-    cursor.execute("DROP TABLE IF EXISTS data")
-    cursor.execute("DROP TABLE IF EXISTS meta")
-    query = """CREATE TABLE IF NOT EXISTS data(
-    gfid           VARCHAR(100) PRIMARY KEY ON CONFLICT IGNORE,
-    changelog_time VARCHAR(100)
-    )"""
-    cursor.execute(query)
-
-    query = """CREATE TABLE IF NOT EXISTS meta(
-    gfid           VARCHAR(100) PRIMARY KEY ON CONFLICT IGNORE,
-    changelog_time VARCHAR(100)
-    )"""
-    cursor.execute(query)
-
-
-def db_record_data(gfid, changelog_time):
-    query = "INSERT INTO data(gfid, changelog_time) VALUES(?, ?)"
-    cursor.execute(query, (gfid, changelog_time))
-
-
-def db_record_meta(gfid, changelog_time):
-    query = "INSERT INTO meta(gfid, changelog_time) VALUES(?, ?)"
-    cursor.execute(query, (gfid, changelog_time))
-
-
-def db_remove_meta(gfid):
-    query = "DELETE FROM meta WHERE gfid = ?"
-    cursor.execute(query, (gfid, ))
-
-
-def db_remove_data(gfid):
-    query = "DELETE FROM data WHERE gfid = ?"
-    cursor.execute(query, (gfid, ))
-
-
-def db_get_data(start, end, limit, offset):
-    query = """SELECT gfid FROM data WHERE changelog_time
-    BETWEEN ? AND ? LIMIT ? OFFSET ?"""
-    cursor.execute(query, (start, end, limit, offset))
-    out = []
-    for row in cursor:
-        out.append(row[0])
-
-    return out
-
-
-def db_get_meta(start, end, limit, offset):
-    query = """SELECT gfid FROM meta WHERE changelog_time
-    BETWEEN ? AND ? LIMIT ? OFFSET ?"""
-    cursor.execute(query, (start, end, limit, offset))
-    out = []
-    for row in cursor:
-        out.append(row[0])
-
-    return out
-
-
-def db_delete_meta_if_exists_in_data():
-    query = """
-    DELETE FROM meta WHERE gfid in
-    (SELECT M.gfid
-     FROM meta M INNER JOIN data D
-     ON M.gfid = D.gfid)
-    """
-    cursor.execute(query)
-
-
-def db_get_data_count():
-    query = "SELECT COUNT(gfid) FROM data"
-    cursor.execute(query)
-    return cursor.fetchone()[0]
-
-
-def db_get_meta_count():
-    query = "SELECT COUNT(gfid) FROM meta"
-    cursor.execute(query)
-    return cursor.fetchone()[0]
diff --git a/geo-replication/syncdaemon/gsyncd.py b/geo-replication/syncdaemon/gsyncd.py
index 918bee0ce1..84b26a4114 100644
--- a/geo-replication/syncdaemon/gsyncd.py
+++ b/geo-replication/syncdaemon/gsyncd.py
@@ -275,27 +275,6 @@ def main_i():
     op.add_option('--log-rsync-performance', default=False,
                   action='store_true')
     op.add_option('--max-rsync-retries', type=int, default=10)
-
-    # This is for stime granularity, Bigger batch will be split into
-    # multiple data batches, On failure it will start from this point
-    # Default value is 1 day changelogs
-    # (4 * 60 * 24 = 5760)
-    #    4 changelogs per minute
-    #   60 min per hr
-    #   24 hrs per day
-    op.add_option('--max-data-changelogs-in-batch', type=int, default=5760)
-
-    # While processing Historical Changelogs above BATCH SIZE is not considered
-    # since all Changelogs to be post processed once, Batching it makes more
-    # rsync retries. (4 * 60 * 24 * 15 = 86400)
-    #    4 changelogs per minute
-    #   60 min per hr
-    #   24 hrs per day
-    #   15 days
-    # This means 15 days changelogs can be processed at once in case of
-    # History scan
-    op.add_option('--max-history-changelogs-in-batch', type=int, default=86400)
-
     op.add_option('--pause-on-start', default=False, action='store_true')
     op.add_option('-L', '--log-level', metavar='LVL')
     op.add_option('-r', '--remote-gsyncd', metavar='CMD',
diff --git a/geo-replication/syncdaemon/master.py b/geo-replication/syncdaemon/master.py
index 3df08e41a1..7d015aee71 100644
--- a/geo-replication/syncdaemon/master.py
+++ b/geo-replication/syncdaemon/master.py
@@ -26,12 +26,6 @@ from syncdutils import Thread, GsyncdError, boolify, escape
 from syncdutils import unescape, gauxpfx, md5hex, selfkill
 from syncdutils import lstat, errno_wrap, FreeObject
 from syncdutils import NoStimeAvailable, PartialHistoryAvailable
-from changelogsdb import db_init, db_record_data, db_record_meta
-from changelogsdb import db_remove_data, db_remove_meta
-from changelogsdb import db_get_data, db_get_meta, db_commit
-from changelogsdb import db_get_data_count, db_get_meta_count
-from changelogsdb import db_delete_meta_if_exists_in_data
-
 
 URXTIME = (-1, 0)
 
@@ -51,10 +45,6 @@ CHANGELOG_ROLLOVER_TIME = 15
 # that batch since stime will get updated after each batch.
 MAX_CHANGELOG_BATCH_SIZE = 727040
 
-# Number of record to query once
-DB_PAGINATION_SIZE_META = 100
-DB_PAGINATION_SIZE_DATA = 1000
-
 # Utility functions to help us to get to closer proximity
 # of the DRY principle (no, don't look for elevated or
 # perspectivistic things here)
@@ -287,7 +277,7 @@ class TarSSHEngine(object):
                     st = lstat(se)
                     if isinstance(st, int):
                         # file got unlinked in the interim
-                        db_remove_data(se)
+                        self.unlinked_gfids.add(se)
                         return True
 
             self.add_job(self.FLAT_DIR_HIERARCHY, 'reg', regjob, f, None, pb)
@@ -322,7 +312,7 @@ class RsyncEngine(object):
                     st = lstat(se)
                     if isinstance(st, int):
                         # file got unlinked in the interim
-                        db_remove_data(se)
+                        self.unlinked_gfids.add(se)
                         return True
 
             self.add_job(self.FLAT_DIR_HIERARCHY, 'reg', regjob, f, None, pb)
@@ -427,6 +417,7 @@ class GMasterCommon(object):
         self.volinfo = None
         self.terminate = False
         self.sleep_interval = 1
+        self.unlinked_gfids = set()
 
     def init_keep_alive(cls):
         """start the keep-alive thread """
@@ -666,11 +657,6 @@ class GMasterCommon(object):
             ret = j[-1]()
             if not ret:
                 succeed = False
-
-        # All the unlinked GFIDs removed from Data and Meta list
-        # Commit the Transaction
-        db_commit()
-
         if succeed and not args[0] is None:
             self.sendmark(path, *args)
         return succeed
@@ -783,12 +769,10 @@ class GMasterChangelogMixin(GMasterCommon):
         pfx = gauxpfx()
         clist = []
         entries = []
-        change_ts = change.split(".")[-1]
+        meta_gfid = set()
+        datas = set()
 
-        # self.data_batch_start is None only in beginning and during
-        # new batch start
-        if self.data_batch_start is None:
-            self.data_batch_start = change_ts
+        change_ts = change.split(".")[-1]
 
         # Ignore entry ops which are already processed in Changelog modes
         ignore_entry_ops = False
@@ -860,10 +844,9 @@ class GMasterChangelogMixin(GMasterCommon):
                     # not fail
                     pt = os.path.join(pfx, ec[0])
                     st = lstat(pt)
-                    if isinstance(st, int):
+                    if pt in datas and isinstance(st, int):
                         # file got unlinked, May be historical Changelog
-                        db_remove_data(pt)
-                        db_remove_meta(pt)
+                        datas.remove(pt)
 
                     if not boolify(gconf.ignore_deletes):
                         if not ignore_entry_ops:
@@ -886,10 +869,10 @@ class GMasterChangelogMixin(GMasterCommon):
                                 # CREATED if source not exists.
                                 entries.append(edct('LINK', stat=st, entry=en,
                                                gfid=gfid))
+
                                 # Here, we have the assumption that only
                                 # tier-gfid.linkto causes this mknod. Add data
-                                db_record_data(os.path.join(pfx, ec[0]),
-                                               change_ts)
+                                datas.add(os.path.join(pfx, ec[0]))
                                 continue
 
                     # stat info. present in the changelog itself
@@ -931,25 +914,48 @@ class GMasterChangelogMixin(GMasterCommon):
                     else:
                         logging.warn('ignoring %s [op %s]' % (gfid, ty))
             elif et == self.TYPE_GFID:
-                db_record_data(os.path.join(pfx, ec[0]), change_ts)
+                # If self.unlinked_gfids is available, then that means it is
+                # retrying the changelog second time. Do not add the GFID's
+                # to rsync job if failed previously but unlinked in master
+                if self.unlinked_gfids and \
+                   os.path.join(pfx, ec[0]) in self.unlinked_gfids:
+                    logging.debug("ignoring data, since file purged interim")
+                else:
+                    datas.add(os.path.join(pfx, ec[0]))
             elif et == self.TYPE_META:
                 if ec[1] == 'SETATTR':  # only setattr's for now...
-                    db_record_meta(os.path.join(pfx, ec[0]), change_ts)
+                    if len(ec) == 5:
+                        # In xsync crawl, we already have stat data
+                        # avoid doing stat again
+                        meta_gfid.add((os.path.join(pfx, ec[0]),
+                                       XCrawlMetadata(st_uid=ec[2],
+                                                      st_gid=ec[3],
+                                                      st_mode=ec[4],
+                                                      st_atime=ec[5],
+                                                      st_mtime=ec[6])))
+                    else:
+                        meta_gfid.add((os.path.join(pfx, ec[0]), ))
                 elif ec[1] == 'SETXATTR' or ec[1] == 'XATTROP' or \
                      ec[1] == 'FXATTROP':
                     # To sync xattr/acls use rsync/tar, --xattrs and --acls
                     # switch to rsync and tar
                     if not boolify(gconf.use_tarssh) and \
                        (boolify(gconf.sync_xattrs) or boolify(gconf.sync_acls)):
-                        db_record_data(os.path.join(pfx, ec[0]), change_ts)
+                        datas.add(os.path.join(pfx, ec[0]))
             else:
                 logging.warn('got invalid changelog type: %s' % (et))
         logging.debug('entries: %s' % repr(entries))
 
+        # Increment counters for Status
+        self.status.inc_value("entry", len(entries))
+        self.files_in_batch += len(datas)
+        self.status.inc_value("data", len(datas))
+
         # sync namespace
         if entries and not ignore_entry_ops:
             # Increment counters for Status
             self.status.inc_value("entry", len(entries))
+
             failures = self.slave.server.entry_ops(entries)
             self.log_failures(failures, 'gfid', gauxpfx(), 'ENTRY')
             self.status.dec_value("entry", len(entries))
@@ -969,53 +975,70 @@ class GMasterChangelogMixin(GMasterCommon):
 
             self.skipped_entry_changelogs_last = change_ts
 
-        # Batch data based on number of changelogs as configured as
-        # gconf.max_data_changelogs_in_batch(Default is 24 hrs)
-        # stime will be set after completion of these batch, so on failure
-        # Geo-rep will progress day by day
-        if (self.num_changelogs > gconf.max_data_changelogs_in_batch):
-            # (Start Changelog TS, End Changelog TS, [Changes])
-            self.data_batches.append([self.data_batch_start, change_ts,
-                                      [change]])
-            self.data_batch_start = None
-            self.num_changelogs = 0
-        else:
-            self.data_batches[-1][1] = change_ts
-            self.data_batches[-1][2].append(change)
-
-    def datas_to_queue(self, start, end):
-        # Paginate db entries and add it to Rsync PostBox
-        offset = 0
-        total_datas = 0
-        while True:
-            # Db Pagination
-            datas = db_get_data(start=start, end=end,
-                                limit=DB_PAGINATION_SIZE_DATA,
-                                offset=offset)
-            if len(datas) == 0:
-                break
-            offset += DB_PAGINATION_SIZE_DATA
-            total_datas += len(datas)
+        # sync metadata
+        if meta_gfid:
+            meta_entries = []
+            for go in meta_gfid:
+                if len(go) > 1:
+                    st = go[1]
+                else:
+                    st = lstat(go[0])
+                if isinstance(st, int):
+                    logging.debug('file %s got purged in the interim' % go[0])
+                    continue
+                meta_entries.append(edct('META', go=go[0], stat=st))
+            if meta_entries:
+                self.status.inc_value("meta", len(entries))
+                failures = self.slave.server.meta_ops(meta_entries)
+                self.log_failures(failures, 'go', '', 'META')
+                self.status.dec_value("meta", len(entries))
+
+        # sync data
+        if datas:
             self.a_syncdata(datas)
-        return total_datas
+            self.datas_in_batch.update(datas)
 
-    def handle_data_sync(self, start, end, changes, done, total_datas):
-        """
-        Wait till all rsync jobs are complete, also handle the retries
-        Update data stime Once Rsync jobs are complete.
-        """
-        retry = False
+    def process(self, changes, done=1):
         tries = 0
+        retry = False
+        self.unlinked_gfids = set()
+        self.files_in_batch = 0
+        self.datas_in_batch = set()
         # Error log disabled till the last round
         self.syncer.disable_errorlog()
+        self.skipped_entry_changelogs_first = None
+        self.skipped_entry_changelogs_last = None
+        self.num_skipped_entry_changelogs = 0
+        self.batch_start_time = time.time()
 
         while True:
-            if retry:
-                self.datas_to_queue(start, end)
+            # first, fire all changelog transfers in parallel. entry and
+            # metadata are performed synchronously, therefore in serial.
+            # However at the end of each changelog, data is synchronized
+            # with syncdata_async() - which means it is serial w.r.t
+            # entries/metadata of that changelog but happens in parallel
+            # with data of other changelogs.
 
-            if retry and tries == (gconf.max_rsync_retries - 1):
-                # Enable Error logging if it is last retry
-                self.syncer.enable_errorlog()
+            if retry:
+                if tries == (int(gconf.max_rsync_retries) - 1):
+                    # Enable Error logging if it is last retry
+                    self.syncer.enable_errorlog()
+
+                # Remove Unlinked GFIDs from Queue
+                for unlinked_gfid in self.unlinked_gfids:
+                    if unlinked_gfid in self.datas_in_batch:
+                        self.datas_in_batch.remove(unlinked_gfid)
+
+                # Retry only Sync. Do not retry entry ops
+                if self.datas_in_batch:
+                    self.a_syncdata(self.datas_in_batch)
+            else:
+                for change in changes:
+                    logging.debug('processing change %s' % change)
+                    self.process_change(change, done, retry)
+                    if not retry:
+                        # number of changelogs processed in the batch
+                        self.turns += 1
 
             # Now we wait for all the data transfers fired off in the above
             # step to complete. Note that this is not ideal either. Ideally
@@ -1038,34 +1061,38 @@ class GMasterChangelogMixin(GMasterCommon):
 
             # @change is the last changelog (therefore max time for this batch)
             if self.syncdata_wait():
+                self.unlinked_gfids = set()
                 if done:
-                    xtl = (int(changes[-1].split('.')[-1]) - 1, 0)
+                    xtl = (int(change.split('.')[-1]) - 1, 0)
                     self.upd_stime(xtl)
                     map(self.changelog_done_func, changes)
                     self.archive_and_purge_changelogs(changes)
 
                 # Reset Data counter after sync
-                self.status.dec_value("data", total_datas)
+                self.status.dec_value("data", self.files_in_batch)
+                self.files_in_batch = 0
+                self.datas_in_batch = set()
                 break
 
             # We do not know which changelog transfer failed, retry everything.
             retry = True
             tries += 1
-            if tries >= gconf.max_rsync_retries:
+            if tries == int(gconf.max_rsync_retries):
                 logging.error('changelogs %s could not be processed '
                               'completely - moving on...' %
                               ' '.join(map(os.path.basename, changes)))
 
                 # Reset data counter on failure
-                self.status.dec_value("data", total_datas)
+                self.status.dec_value("data", self.files_in_batch)
+                self.files_in_batch = 0
+                self.datas_in_batch = set()
 
                 if done:
-                    xtl = (int(changes[-1].split('.')[-1]) - 1, 0)
+                    xtl = (int(change.split('.')[-1]) - 1, 0)
                     self.upd_stime(xtl)
                     map(self.changelog_done_func, changes)
                     self.archive_and_purge_changelogs(changes)
                 break
-
             # it's either entry_ops() or Rsync that failed to do it's
             # job. Mostly it's entry_ops() [which currently has a problem
             # of failing to create an entry but failing to return an errno]
@@ -1076,8 +1103,21 @@ class GMasterChangelogMixin(GMasterCommon):
             logging.warn('incomplete sync, retrying changelogs: %s' %
                          ' '.join(map(os.path.basename, changes)))
 
+            # Reset the Data counter before Retry
+            self.status.dec_value("data", self.files_in_batch)
+            self.files_in_batch = 0
             time.sleep(0.5)
 
+        # Log the Skipped Entry ops range if any
+        if self.skipped_entry_changelogs_first is not None and \
+           self.skipped_entry_changelogs_last is not None:
+            logging.info("Skipping already processed entry "
+                         "ops from CHANGELOG.{0} to CHANGELOG.{1} "
+                         "Num: {2}".format(
+                             self.skipped_entry_changelogs_first,
+                             self.skipped_entry_changelogs_last,
+                             self.num_skipped_entry_changelogs))
+
         # Log Current batch details
         if changes:
             logging.info(
@@ -1091,94 +1131,6 @@ class GMasterChangelogMixin(GMasterCommon):
                     repr(self.get_data_stime()),
                     repr(self.get_entry_stime())))
 
-    def process(self, changes, done=1):
-        retry = False
-        first_changelog_ts = changes[0].split(".")[-1]
-
-        db_init(os.path.join(self.tempdir, "temp_changelogs.db"))
-
-        self.skipped_entry_changelogs_first = None
-        self.skipped_entry_changelogs_last = None
-        self.num_skipped_entry_changelogs = 0
-        self.batch_start_time = time.time()
-        # (Start Changelog TS, End Changelog TS, [Changes])
-        self.data_batches = [[first_changelog_ts, first_changelog_ts, []]]
-        self.data_batch_start = None
-        self.num_changelogs = 0
-
-        for change in changes:
-            logging.debug('processing change %s' % change)
-            self.process_change(change, done, retry)
-            # number of changelogs processed in the batch
-            self.turns += 1
-
-        # Rsync/Tar will preserve permissions, so if a GFID exists
-        # in data queue then it syncs meta details too. Remove
-        # all meta from meta table if exists in data table
-        db_delete_meta_if_exists_in_data()
-
-        # All the Data/Meta populated, Commit the Changes in Db
-        db_commit()
-
-        # Log the Skipped Entry ops range if any
-        if self.skipped_entry_changelogs_first is not None and \
-           self.skipped_entry_changelogs_last is not None:
-            logging.info("Skipping already processed entry "
-                         "ops from CHANGELOG.{0} to CHANGELOG.{1} "
-                         "Num: {2}".format(
-                             self.skipped_entry_changelogs_first,
-                             self.skipped_entry_changelogs_last,
-                             self.num_skipped_entry_changelogs))
-
-        # Entry Changelogs syncing finished
-        logging.info("Syncing Entries completed in {0:.4f} seconds "
-                     "CHANGELOG.{1} - CHANGELOG.{2} "
-                     "Num: {3}".format(
-                         time.time() - self.batch_start_time,
-                         changes[0].split(".")[-1],
-                         changes[-1].split(".")[-1],
-                         len(changes)))
-
-        # Update Status Data and Meta Count
-        self.status.inc_value("data", db_get_data_count())
-        self.status.inc_value("meta", db_get_meta_count())
-
-        for b in self.data_batches:
-            # Add to data Queue, so that Rsync will start parallelly
-            # while syncing Meta ops
-            total_datas = self.datas_to_queue(b[0], b[1])
-
-            # Sync Meta
-            offset = 0
-            while True:
-                # Db Pagination
-                meta_gfids = db_get_meta(start=b[0], end=b[1],
-                                         limit=DB_PAGINATION_SIZE_META,
-                                         offset=offset)
-                if len(meta_gfids) == 0:
-                    break
-                offset += DB_PAGINATION_SIZE_META
-
-                # Collect required information for GFIDs which
-                # exists in Master
-                meta_entries = []
-                for go in meta_gfids:
-                    st = lstat(go)
-                    if isinstance(st, int):
-                        logging.debug('file %s got purged in the '
-                                      'interim' % go)
-                        continue
-                    meta_entries.append(edct('META', go=go, stat=st))
-
-                if meta_entries:
-                    failures = self.slave.server.meta_ops(meta_entries)
-                    self.log_failures(failures, 'go', '', 'META')
-                    self.status.dec_value("meta", len(meta_entries))
-
-            # Sync Data, Rsync already started syncing the files
-            # wait for the completion and retry if required.
-            self.handle_data_sync(b[0], b[1], b[2], done, total_datas)
-
     def upd_entry_stime(self, stime):
         self.slave.server.set_entry_stime(self.FLAT_DIR_HIERARCHY,
                                           self.uuid,
@@ -1206,12 +1158,7 @@ class GMasterChangelogMixin(GMasterCommon):
         remote_node_ip = node.split(":")[0]
         self.status.set_slave_node(remote_node_ip)
 
-    def changelogs_batch_process(self, changes, single_batch=False):
-        if single_batch and changes:
-            logging.debug('processing changes %s' % repr(changes))
-            self.process(changes)
-            return
-
+    def changelogs_batch_process(self, changes):
         changelogs_batches = []
         current_size = 0
         for c in changes:
@@ -1245,6 +1192,7 @@ class GMasterChangelogMixin(GMasterCommon):
         changes = self.changelog_agent.getchanges()
         if changes:
             if data_stime:
+                logging.info("slave's time: %s" % repr(data_stime))
                 processed = [x for x in changes
                              if int(x.split('.')[-1]) < data_stime[0]]
                 for pr in processed:
@@ -1313,15 +1261,13 @@ class GMasterChangeloghistoryMixin(GMasterChangelogMixin):
         # to be processed. returns positive value as number of changelogs
         # to be processed, which will be fetched using
         # history_getchanges()
-        num_scanned_changelogs = self.changelog_agent.history_scan()
-        num_changelogs = num_scanned_changelogs
-        changes = []
-        while num_scanned_changelogs > 0:
+        while self.changelog_agent.history_scan() > 0:
             self.crawls += 1
 
-            changes += self.changelog_agent.history_getchanges()
+            changes = self.changelog_agent.history_getchanges()
             if changes:
                 if data_stime:
+                    logging.info("slave's time: %s" % repr(data_stime))
                     processed = [x for x in changes
                                  if int(x.split('.')[-1]) < data_stime[0]]
                     for pr in processed:
@@ -1330,18 +1276,7 @@ class GMasterChangeloghistoryMixin(GMasterChangelogMixin):
                         self.changelog_done_func(pr)
                         changes.remove(pr)
 
-            if num_changelogs > gconf.max_history_changelogs_in_batch:
-                self.changelogs_batch_process(changes, single_batch=True)
-                num_changelogs = 0
-                changes = []
-
-            num_scanned_changelogs = self.changelog_agent.history_scan()
-            num_changelogs += num_scanned_changelogs
-
-        # If Last batch is not processed with MAX_NUM_CHANGELOGS_IN_BATCH
-        # condition above
-        if changes:
-            self.changelogs_batch_process(changes, single_batch=True)
+            self.changelogs_batch_process(changes)
 
         history_turn_time = int(time.time()) - self.history_crawl_start_time
 
diff --git a/geo-replication/syncdaemon/resource.py b/geo-replication/syncdaemon/resource.py
index 91ca1916f6..00bf4cb9d5 100644
--- a/geo-replication/syncdaemon/resource.py
+++ b/geo-replication/syncdaemon/resource.py
@@ -31,6 +31,7 @@ import shutil
 from gconf import gconf
 import repce
 from repce import RepceServer, RepceClient
+from master import gmaster_builder
 import syncdutils
 from syncdutils import GsyncdError, select, privileged, boolify, funcode
 from syncdutils import umask, entry2pb, gauxpfx, errno_wrap, lstat
@@ -1408,7 +1409,6 @@ class GLUSTER(AbstractUrl, SlaveLocal, SlaveRemote):
     def gmaster_instantiate_tuple(self, slave):
         """return a tuple of the 'one shot' and the 'main crawl'
         class instance"""
-        from master import gmaster_builder
         return (gmaster_builder('xsync')(self, slave),
                 gmaster_builder()(self, slave),
                 gmaster_builder('changeloghistory')(self, slave))