From 7eb9d8f732d1d47eec5685603ba6407caf4aa7ca Mon Sep 17 00:00:00 2001
From: Guido Trotter <ultrotter@google.com>
Date: Mon, 18 Aug 2008 12:51:35 +0000
Subject: [PATCH] Parallelize LUQueryInstances
This first version acquires a shared lock on all requested instances and
their nodes. In the future it can be improved by acquiring less locks if
no dynamic fields have been asked, and/or by locking just primary nodes.
Reviewed-by: imsnah
---
lib/cmdlib.py | 36 +++++++++++++++++++++++++++++-------
1 file changed, 29 insertions(+), 7 deletions(-)
diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index f8db0d1e0..39a5d67e3 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -2452,13 +2452,9 @@ class LUQueryInstances(NoHooksLU):
"""
_OP_REQP = ["output_fields", "names"]
+ REQ_BGL = False
- def CheckPrereq(self):
- """Check prerequisites.
-
- This checks that the fields required are valid output fields.
-
- """
+ def ExpandNames(self):
self.dynamic_fields = frozenset(["oper_state", "oper_ram", "status"])
_CheckOutputFields(static=["name", "os", "pnode", "snodes",
"admin_state", "admin_ram",
@@ -2467,7 +2463,33 @@ class LUQueryInstances(NoHooksLU):
dynamic=self.dynamic_fields,
selected=self.op.output_fields)
- self.wanted = _GetWantedInstances(self, self.op.names)
+ self.needed_locks = {}
+ self.share_locks[locking.LEVEL_INSTANCE] = 1
+ self.share_locks[locking.LEVEL_NODE] = 1
+
+ # TODO: we could lock instances (and nodes) only if the user asked for
+ # dynamic fields. For that we need atomic ways to get info for a group of
+ # instances from the config, though.
+ if not self.op.names:
+ self.needed_locks[locking.LEVEL_INSTANCE] = None # Acquire all
+ else:
+ self.needed_locks[locking.LEVEL_INSTANCE] = \
+ _GetWantedInstances(self, self.op.names)
+
+ self.needed_locks[locking.LEVEL_NODE] = []
+ self.recalculate_locks[locking.LEVEL_NODE] = 'replace'
+
+ def DeclareLocks(self, level):
+ # TODO: locking of nodes could be avoided when not querying them
+ if level == locking.LEVEL_NODE:
+ self._LockInstancesNodes()
+
+ def CheckPrereq(self):
+ """Check prerequisites.
+
+ """
+ # This of course is valid only if we locked the instances
+ self.wanted = self.needed_locks[locking.LEVEL_INSTANCE]
def Exec(self, feedback_fn):
"""Computes the list of nodes and their attributes.
--
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