default images.fix.orientation to false

1 files changed, 0 insertions, 109 deletions

diff --git a/note/replication.txt b/note/replication.txt
deleted file mode 100644
index a151e80c3..000000000
--- a/note/replication.txt
+++ /dev/null
@@ -1,109 +0,0 @@
-1. each file can choose the replication factor
-2. replication granularity is in volume level
-3. if not enough spaces, we can automatically decrease some volume's the replication factor, especially for cold data
-4. plan to support migrating data to cheaper storage
-5. plan to manual volume placement, access-based volume placement, auction based volume placement
-
-When a new volume server is started, it reports 
-  1. how many volumes it can hold
-  2. current list of existing volumes and each volume's replication type
-Each volume server remembers:
-  1. current volume ids
-  2. replica locations are read from the master
-
-The master assign volume ids based on
-  1. replication factor
-     data center, rack
-  2. concurrent write support
-On master, stores the replication configuration
-{
-  replication:{
-    {type:"00", min_volume_count:3, weight:10},
-    {type:"01", min_volume_count:2, weight:20},
-    {type:"10", min_volume_count:2, weight:20},
-    {type:"11", min_volume_count:3, weight:30},
-    {type:"20", min_volume_count:2, weight:20}
-  },
-  port:9333,
-}
-Or manually via command line
-  1. add volume with specified replication factor
-  2. add volume with specified volume id
-
-
-If duplicated volume ids are reported from different volume servers, 
-the master determines the replication factor of the volume,
-if less than the replication factor, the volume is in readonly mode
-if more than the replication factor, the volume will purge the smallest/oldest volume
-if equal, the volume will function as usual
-
-
-Use cases:
-  on volume server
-    1. weed volume -mserver="xx.xx.xx.xx:9333" -publicUrl="good.com:8080" -dir="/tmp" -volumes=50
-  on weed master
-    1. weed master -port=9333
-      generate a default json configuration file if doesn't exist
-      
-Bootstrap
-  1. at the very beginning, the system has no volumes at all.
-When data node starts:
-  1. each data node send to master its existing volumes and max volume blocks
-  2. master remembers the topology/data_center/rack/data_node/volumes
-     for each replication level, stores
-       volume id ~ data node
-       writable volume ids
-If any "assign" request comes in
-  1. find a writable volume with the right replicationLevel
-  2. if not found, grow the volumes with the right replication level
-  3. return a writable volume to the user
-
-  
-  for data node:
-    0. detect existing volumes DONE
-    1. onStartUp, and periodically, send existing volumes and maxVolumeCount  store.Join(), DONE
-    2. accept command to grow a volume( id + replication level)  DONE
-       /admin/assign_volume?volume=some_id&replicationType=01
-    3. accept setting volumeLocationList  DONE
-       /admin/set_volume_locations_list?volumeLocationsList=[{Vid:xxx,Locations:[loc1,loc2,loc3]}]
-    4. for each write, pass the write to the next location, (Step 2)
-       POST method should accept an index, like ttl, get decremented every hop
-  for master:
-    1. accept data node's report of existing volumes and maxVolumeCount ALREADY EXISTS /dir/join
-    2. periodically refresh for active data nodes, and adjust writable volumes
-    3. send command to grow a volume(id + replication level)  DONE
-    5. accept lookup for volume locations    ALREADY EXISTS /dir/lookup
-    6. read topology/datacenter/rack layout
-
-An algorithm to allocate volumes evenly, but may be inefficient if free volumes are plenty:
-input: replication=xyz
-algorithm:
-ret_dcs = []
-foreach dc that has y+z+1 volumes{
-  ret_racks = []
-  foreach rack with z+1 volumes{
-    ret = select z+1 servers with 1 volume
-  if ret.size()==z+1 {
-    ret_racks.append(ret)
-  }
-  }
-  randomly pick one rack from ret_racks
-  ret += select y racks with 1 volume each
-  if ret.size()==y+z+1{
-    ret_dcs.append(ret)
-  }
-}
-randomly pick one dc from ret_dcs
-ret += select x data centers with 1 volume each
-
-A simple replica placement algorithm, but may fail when free volume slots are not plenty:
-ret := []volumes
-dc = randomly pick 1 data center with y+z+1 volumes
-  rack = randomly pick 1 rack with z+1 volumes
-    ret = ret.append(randomly pick z+1 volumes)
-  ret = ret.append(randomly pick y racks with 1 volume)
-ret = ret.append(randomly pick x data centers with 1 volume)
-
-
-TODO:
-  1. replicate content to the other server if the replication type needs replicas