updated CHANGELOG (#3690)

CHANGELOG

@@ -1,9 +1,9 @@
 devel
 -----
 
-* add readonly mode rest API
+* add readonly mode REST API
 
-* allow compilation of ArangoDB with g++7
+* allow compilation of ArangoDB source code with g++7
 
 * AQL: during a traversal if a vertex is not found. It will not print an ERROR to the log and continue
   with a NULL value, but will register a warning at the query and continue with a NULL value.
@@ -11,35 +11,11 @@ devel
   vertex which is perfectly valid, but it may be a n issue on the data model, so users
   can directly see it on the query now and do not "by accident" have to check the LOG output.
 
-* UI: fixed event cleanup in cluster shards view
-
-* fixed issue #3618: Inconsistent behavior of OR statement with object bind parameters
-
 * potential fix for issue #3562: Document WITHIN_RECTANGLE not found
 
-* increase default maximum number of V8 contexts to at least 16 if not 
+* introduce `enforceReplicationFactor` attribute for creating collections: 
-  explicitly configured otherwise. the mode for determining the actual maximum
+  this optional parameter controls if the coordinator should bail out during collection 
-  value of V8 contexts is unchanged and works as follows:
+  creation if there are not enough DBServers available for the desired `replicationFactor`.
-  - if explicitly set, the value of the configuration option `--javascript.v8-contexts`
-    is used as the maximum number of V8 contexts
-  - when the option is not set, the maximum number of V8 contexts is determined
-    by the configuration option `--server.threads` if that option is set. if 
-    `--server.threads` is not set, then the maximum number of V8 contexts is the
-    server's reported hardware concurrency (number of processors visible
-    to the arangod process). if that would result in a maximum value of 16 in 
-    any of these two cases, then the maximum value will be increased to 16.
-
-* fixed issue #3447: ArangoError 1202: AQL: NotFound: (while executing) when 
-  updating collection
-
-* potential fix for issue #3581: Unexpected "rocksdb unique constraint 
-  violated" with unique hash index
-
-* fix agency precondition check for complex objects
-
-* introduce `enforceReplicationFactor`: An optional parameter controlling
-  if the server should bail out during collection creation if there are not
-  enough DBServers available for the desired `replicationFactor`.
 
 * fixed issue #3516: Show execution time in arangosh
     
@@ -66,15 +42,15 @@ devel
 
 * make AQL `DISTINCT` not change the order of the results it is applied on
 
-* enable JEMalloc background thread for purging and returning unused memory
-  back to the operating system (Linux only)
-
 * incremental transfer of initial collection data now can handle partial 
   responses for a chunk, allowing the leader/master to send smaller chunks 
   (in terms of HTTP response size) and limit memory usage
 
+  this optimization is only active if client applications send the "offset" parameter
+  in their requests to PUT `/_api/replication/keys/<id>?type=docs`
+
 * initial creation of shards for cluster collections is now faster with
-  replicationFactor values bigger than 1. this is achieved by an optimization
+  `replicationFactor` values bigger than 1. this is achieved by an optimization
   for the case when the collection on the leader is still empty
 
 * potential fix for issue #3517: several "filesystem full" errors in logs 
@@ -84,7 +60,7 @@ devel
 
 * show C++ function name of call site in ArangoDB log output
 
-  This requires option `--log.line-number` to be set to *true*
+  this requires option `--log.line-number` to be set to *true*
 
 * UI: added word wrapping to query editor
 
@@ -120,7 +96,7 @@ devel
 
 * removed `--compat28` parameter from arangodump and replication API
   
-  old Arango versions will no longer be supported by these tools.
+  older ArangoDB versions will no longer be supported by these tools.
 
 * increase the recommended value for `/proc/sys/vm/max_map_count` to a value
   eight times as high as the previous recommended value. Increasing the
@@ -133,19 +109,64 @@ devel
       WARNING {memory} execute 'sudo sysctl -w "vm.max_map_count=512000"'
 
 
-v3.2.7 (XXXX-XX-XX)
+v3.2.7 (2017-11-14)
 -------------------
 
+* fixed some undefined behavior in some internal value caches for AQL GatherNodes
+  and SortNodes, which could have led to sorted results being effectively not
+  correctly sorted.
 
-* improved the speed of shardDistribution in cluster, by moving it to c++. It is now guaranteed
+* make the replication applier for the RocksDB engine start automatically after a
-  return after ~2 seconds even if the entire cluster is unresponsive.
+  restart of the server if the applier was configured with its `autoStart` property
+  set to `true`. previously the replication appliers were only automatically restarted
+  at server start for the MMFiles engine.
 
-* enable JEMalloc background thread for purging and returning unused memory
+* fixed arangodump batch size adaptivity in cluster mode and upped default batch size
-  back to the operating system (Linux only)
+  for arangodump
+
+  these changes speed up arangodump in cluster context
+
+* smart graphs now return a proper inventory in response to replication inventory
+  requests
+
+* fixed issue #3618: Inconsistent behavior of OR statement with object bind parameters
+
+* only users with read/write rights on the "_system" database can now execute
+  "_admin/shutdown" as well as modify properties of the write-ahead log (WAL)
+ 
+* increase default maximum number of V8 contexts to at least 16 if not explicitly 
+  configured otherwise. 
+  the procedure for determining the actual maximum value of V8 contexts is unchanged 
+  apart from the value `16` and works as follows:
+  - if explicitly set, the value of the configuration option `--javascript.v8-contexts`
+    is used as the maximum number of V8 contexts
+  - when the option is not set, the maximum number of V8 contexts is determined
+    by the configuration option `--server.threads` if that option is set. if 
+    `--server.threads` is not set, then the maximum number of V8 contexts is the
+    server's reported hardware concurrency (number of processors visible
+    to the arangod process). if that would result in a maximum value of less than 16 
+    in any of these two cases, then the maximum value will be increased to 16.
+
+* fixed issue #3447: ArangoError 1202: AQL: NotFound: (while executing) when 
+  updating collection
+
+* potential fix for issue #3581: Unexpected "rocksdb unique constraint 
+  violated" with unique hash index
+
+* fixed geo index optimizer rule for geo indexes with a single (array of coordinates)
+  attribute.
+
+* improved the speed of the shards overview in cluster (API endpoint /_api/cluster/shardDistribution API)
+  It is now guaranteed to return after ~2 seconds even if the entire cluster is unresponsive.
 
 * fix agency precondition check for complex objects
   this fixes issues with several CAS operations in the agency
 
+* several fixes for agency restart and shutdown
+
+* the cluster-internal representation of planned collection objects is now more 
+  lightweight than before, using less memory and not allocating any cache for indexes
+  etc.
 
 * fixed issue #3403: How to kill long running AQL queries with the browser console's
   AQL (display issue)
@@ -153,14 +174,54 @@ v3.2.7 (XXXX-XX-XX)
 * fixed issue #3549: server reading ENGINE config file fails on common standard 
   newline character
 
+* UI: fixed error notifications for collection modifications
+
+* several improvements for the truncate operation on collections:
+
+  * the timeout for the truncate operation was increased in cluster mode in
+    order to prevent too frequent "could not truncate collection" errors
+
+  * after a truncate operation, collections in MMFiles still used disk space.
+    to reclaim disk space used by truncated collection, the truncate actions 
+    in the web interface and from the ArangoShell now issue an extra WAL flush
+    command (in cluster mode, this command is also propagated to all servers).
+    the WAL flush allows all servers to write out any pending operations into the 
+    datafiles of the truncated collection. afterwards, a final journal rotate 
+    command is sent, which enables the compaction to entirely remove all datafiles 
+    and journals for the truncated collection, so that all disk space can be
+    reclaimed
+
+  * for MMFiles a special method will be called after a truncate operation so that
+    all indexes of the collection can free most of their memory. previously some
+    indexes (hash and skiplist indexes) partially kept already allocated memory 
+    in order to avoid future memory allocations
+
+  * after a truncate operation in the RocksDB engine, an additional compaction
+    will be triggered for the truncated collection. this compaction removes all
+    deletions from the key space so that follow-up scans over the collection's key
+    range do not have to filter out lots of already-removed values
+
+  These changes make truncate operations potentially more time-consuming than before,
+  but allow for memory/disk space savings afterwards.
+
+* enable JEMalloc background threads for purging and returning unused memory
+  back to the operating system (Linux only)
+
+  JEMalloc will create its background threads on demand. The number of background 
+  threads is capped by the number of CPUs or active arenas. The background threads run
+  periodically and purge unused memory pages, allowing memory to be returned to the
+  operating system.
+
+  This change will make the arangod process create several additional threads.
+  It is accompanied by an increased `TasksMax` value in the systemd service configuration
+  file for the arangodb3 service.
+
 * upgraded bundled V8 engine to bugfix version v5.7.492.77
 
-  the upgrade fixes a memory leak in upstream V8 described in 
+  this upgrade fixes a memory leak in upstream V8 described in 
   https://bugs.chromium.org/p/v8/issues/detail?id=5945 that will result in memory
   chunks only getting uncommitted but not unmapped
 
-* UI: fixed error notifications for collection modifications
-
 
 v3.2.6 (2017-10-26)
 -------------------