updated documentation

CHANGELOG

@@ -39,7 +39,17 @@ shards.
 
       db._query("FOR i IN 1..100000 SORT i RETURN i", {}, { options: { memoryLimit: 100000 } });
 
-* added startup option --query.memory-limit
+  This option limits the default maximum amount of memory (in bytes) that a single 
+  AQL query can use.
+  When a single AQL query reaches the specified limit value, the query will be
+  aborted with a *resource limit exceeded* exception. In a cluster, the memory
+  accounting is done per shard, so the limit value is effectively a memory limit per
+  query per shard.
+
+  The global limit value can be overriden per query by setting the *memoryLimit* 
+  option value for individual queries when running an AQL query. 
+
+* added server startup option `--query.memory-limit`
 
 * added convenience function to create vertex-centric indexes.
 Usage: `db.collection.ensureVertexCentricIndex("label", {type: "hash", direction: "outbound"})`

Documentation/Books/AQL/Invocation/WithArangosh.mdpp

@@ -97,7 +97,10 @@ You also will find warnings in here; If you're designing queries on the shell be
 
 To set a memory limit for the query, pass *options* to the *_query* method.
 The memory limit specifies the maximum number of bytes that the query is
-allowed to use:
+allowed to use. When a single AQL query reaches the specified limit value, 
+the query will be aborted with a *resource limit exceeded* exception. In a 
+cluster, the memory accounting is done per shard, so the limit value is 
+effectively a memory limit per query per shard.
 
     @startDocuBlockInline 02_workWithAQL_memoryLimit
     @EXAMPLE_ARANGOSH_OUTPUT{02_workWithAQL_memoryLimit}
@@ -108,6 +111,10 @@ allowed to use:
     @END_EXAMPLE_ARANGOSH_OUTPUT
     @endDocuBlock 02_workWithAQL_memoryLimit
 
+If no memory limit is specified, then the server default value (controlled by
+startup option *--query.memory-limit* will be used for restricting the maximum amount 
+of memory the query can use. A memory limit value of *0* means that the maximum
+amount of memory for the query is not restricted. 
 
 ### with _createStatement (ArangoStatement)
 

Documentation/Books/HTTP/AqlQueryCursor/QueryResults.mdpp

@@ -198,3 +198,32 @@ Content-type: application/json; charset=utf-8
   "code" : 201
 }
 ```
+
+### Setting a memory limit
+
+To set a memory limit for the query, the *memoryLimit* option can be passed to
+the server.
+The memory limit specifies the maximum number of bytes that the query is
+allowed to use. When a single AQL query reaches the specified limit value, 
+the query will be aborted with a *resource limit exceeded* exception. In a 
+cluster, the memory accounting is done per shard, so the limit value is 
+effectively a memory limit per query per shard.
+
+```js
+> curl --data @- -X POST --dump - http://localhost:8529/_api/cursor
+{ "query" : "FOR i IN 1..100000 SORT i RETURN i", "memoryLimit" : 100000 }
+
+HTTP/1.1 500 Internal Server Error
+Server: ArangoDB
+Connection: Keep-Alive
+Content-Type: application/json; charset=utf-8
+Content-Length: 115
+
+{"error":true,"errorMessage":"query would use more memory than allowed (while executing)","code":500,"errorNum":32}
+```
+
+If no memory limit is specified, then the server default value (controlled by
+startup option *--query.memory-limit* will be used for restricting the maximum amount 
+of memory the query can use. A memory limit value of *0* means that the maximum
+amount of memory for the query is not restricted. 
+

Documentation/Books/Manual/Administration/Configuration/GeneralArangod.mdpp

@@ -329,6 +329,22 @@ directory as argument.
 @startDocuBlock databaseForceSyncProperties
 
 
+### Limiting memory for AQL queries
+
+`--query.memory-limit value`
+
+The default maximum amount of memory (in bytes) that a single AQL query can use.
+When a single AQL query reaches the specified limit value, the query will be
+aborted with a *resource limit exceeded* exception. In a cluster, the memory
+accounting is done per shard, so the limit value is effectively a memory limit per
+query per shard.
+
+The global limit value can be overriden per query by setting the *memoryLimit* 
+option value for individual queries when running an AQL query. 
+
+The default value is *0*, meaning that there is no memory limit.
+
+
 ### Enable/disable AQL query tracking
 
 `--query.tracking flag`

Documentation/Books/Manual/Administration/Configuration/Wal.mdpp

@@ -46,6 +46,11 @@ not present, it will be created.
 <!-- arangod/Wal/LogfileManager.h -->
 @startDocuBlock WalLogfileSyncInterval
 
+### Flush timeout
+
+<!-- arangod/Wal/LogfileManager.h -->
+@startDocuBlock WalLogfileFlushTimeout
+
 ### Throttling
 
 <!-- arangod/Wal/LogfileManager.h -->

Documentation/DocuBlocks/WalLogfileFlushTimeout.md

@@ -0,0 +1,11 @@
+
+@startDocuBlock WalLogfileFlushTimeout
+@brief WAL flush timeout
+`--wal.flush-timeout
+
+The timeout (in milliseconds) that ArangoDB will at most wait when flushing
+a full WAL logfile to disk. When the timeout is reached and the flush is
+not completed, the operation that requested the flush will fail with a 
+*lock timeout* error.
+@endDocuBlock
+