return SERVER ERROR when availability blocks an operation

RB_ID=93662

src/main/scala/net/lag/kestrel/MemcacheHandler.scala

@@ -63,7 +63,9 @@ class MemcacheHandler(
  handle(request)
  } catch {
  case e: AvailabilityException =>
- Future(new MemcacheResponse("ERROR") then Codec.Disconnect)
+ // kestrel-client ruby gem will retry (if configured) on SERVER_ERROR, but
+ // not on ERROR or CLIENT_ERROR
+ Future(new MemcacheResponse("SERVER_ERROR") then Codec.Disconnect)
  }
  }
 

src/test/scala/net/lag/kestrel/KestrelHandlerSpec.scala

@@ -300,5 +300,33 @@ class KestrelHandlerSpec extends Specification with JMocker with ClassMocker wit
  }
  }
  }
+
+ "respect server status" in {
+ "by blocking get when reads are blocked" in {
+ withTempFolder {
+ queues = new QueueCollection(folderName, timer, scheduler, config, Nil, Nil)
+ val serverStatus = mock[ServerStatus]
+ val handler = new FakeKestrelHandler(queues, 10, Some(serverStatus))
+ expect {
+ one(serverStatus).blockReads willReturn true
+ }
+
+ handler.getItem("q", None, false, false) must throwAn[AvailabilityException]
+ }
+ }
+
+ "by blocking set when writes are blocked" in {
+ withTempFolder {
+ queues = new QueueCollection(folderName, timer, scheduler, config, Nil, Nil)
+ val serverStatus = mock[ServerStatus]
+ val handler = new FakeKestrelHandler(queues, 10, Some(serverStatus))
+ expect {
+ one(serverStatus).blockWrites willReturn true
+ }
+
+ handler.setItem("q", 0, None, Array[Byte](1,2,3,4)) must throwAn[AvailabilityException]
+ }
+ }
+ }
  }
 }

src/test/scala/net/lag/kestrel/MemcacheHandlerSpec.scala

@@ -465,6 +465,18 @@ class MemcacheHandlerSpec extends Specification with JMocker with ClassMocker {
  }
  }
 
+ "availability exception returns SERVER_ERROR" in {
+ val serverStatus = mock[ServerStatus]
+ expect {
+ one(connection).remoteAddress willReturn address
+ one(serverStatus).blockReads willReturn true
+ }
+
+ val memcacheHandler = new MemcacheHandler(connection, queueCollection, 10, Some(serverStatus))
+
+ memcacheHandler(toReq("get q"))() mustEqual MemcacheResponse("SERVER_ERROR", None)
+ }
+
  "unknown command" in {
  expect {
  one(connection).remoteAddress willReturn address