The Worldwide LHC Computing Grid relies on the network as a critical part of its infrastructure and therefore needs to guarantee effective network usage and prompt detection and resolution of any ...network issues, including connection failures, congestion, traffic routing, etc. The WLCG Network and Transfer Metrics project aims to integrate and combine all network-related monitoring data collected by the WLCG infrastructure. This includes FTS monitoring information, monitoring data from the XRootD federation, as well as results of the perfSONAR tests. The main challenge consists of further integrating and analyzing this information in order to allow the optimizing of data transfers and workload management systems of the LHC experiments. In this contribution, we present our activity in commissioning WLCG perfSONAR network and integrating network and transfer metrics: We motivate the need for the network performance monitoring, describe the main use cases of the LHC experiments as well as status and evolution in the areas of configuration and capacity management, datastore and analytics, including integration of transfer and network metrics and operations and support.
IPv6 Security Babik, M; Chudoba, J; Dewhurst, A ...
Journal of physics. Conference series,
10/2017, Volume:
898, Issue:
10
Journal Article
Peer reviewed
Open access
IPv4 network addresses are running out and the deployment of IPv6 networking in many places is now well underway. Following the work of the HEPiX IPv6 Working Group, a growing number of sites in the ...Worldwide Large Hadron Collider Computing Grid (WLCG) are deploying dual-stack IPv6/IPv4 services. The aim of this is to support the use of IPv6-only clients, i.e. worker nodes, virtual machines or containers. The IPv6 networking protocols while they do contain features aimed at improving security also bring new challenges for operational IT security. The lack of maturity of IPv6 implementations together with the increased complexity of some of the protocol standards raise many new issues for operational security teams. The HEPiX IPv6 Working Group is producing guidance on best practices in this area. This paper considers some of the security concerns for WLCG in an IPv6 world and presents the HEPiX IPv6 working group guidance for the system administrators who manage IT services on the WLCG distributed infrastructure, for their related site security and networking teams and for developers and software engineers working on WLCG applications.
The fraction of Internet traffic carried over IPv6 continues to grow rapidly. IPv6 support from network hardware vendors and carriers is pervasive and becoming mature. A network infrastructure ...upgrade often offers sites an excellent window of opportunity to configure and enable IPv6. There is a significant overhead when setting up and maintaining dual-stack machines, so where possible sites would like to upgrade their services directly to IPv6 only. In doing so, they are also expediting the transition process towards its desired completion. While the LHC experiments accept there is a need to move to IPv6, it is currently not directly affecting their work. Sites are unwilling to upgrade if they will be unable to run LHC experiment workflows. This has resulted in a very slow uptake of IPv6 from WLCG sites. For several years the HEPiX IPv6 Working Group has been testing a range of WLCG services to ensure they are IPv6 compliant. Several sites are now running many of their services as dual-stack. The working group, driven by the requirements of the LHC VOs to be able to use IPv6-only opportunistic resources, continues to encourage wider deployment of dual-stack services to make the use of such IPv6-only clients viable. This paper presents the working group's plan and progress so far to allow sites to deploy IPv6-only CPU resources. This includes making experiment central services dual-stack as well as a number of storage services. The monitoring, accounting and information services that are used by jobs also need to be upgraded. Finally the VO testing that has taken place on hosts connected via IPv6-only is reported.
The production deployment of IPv6 on WLCG Bernier, J; Campana, S; Chadwick, K ...
Journal of physics. Conference series,
01/2015, Volume:
664, Issue:
5
Journal Article
Peer reviewed
Open access
The world is rapidly running out of IPv4 addresses; the number of IPv6 end systems connected to the internet is increasing; WLCG and the LHC experiments may soon have access to worker nodes and/or ...virtual machines (VMs) possessing only an IPv6 routable address. The HEPiX IPv6 Working Group has been investigating, testing and planning for dual-stack services on WLCG for several years. Following feedback from our working group, many of the storage technologies in use on WLCG have recently been made IPv6-capable. This paper presents the IPv6 requirements, tests and plans of the LHC experiments together with the tests performed on the group's IPv6 test-bed. This is primarily aimed at IPv6-only worker nodes or VMs accessing several different implementations of a global dual-stack federated storage service. Finally the plans for deployment of production dual-stack WLCG services are presented.
Since transdermal scopolamine (TS) seems effective against seasickness, we compared its antiemetic effect with intravenous droperidol (DHBP), our routine antidote for postoperative emesis. Ninety-six ...female patients (ASA I-II) scheduled for short-stay surgery were randomly allocated to three study groups after giving their informed consent. The three groups were as follows: TS adhesive, delivering 140 micrograms initially and 5 micrograms/h thereafter + placebo 0.5 ml i.v. 5 min before the end of surgery; transdermal placebo adhesive preoperatively + DHBP 0.5 ml (1.25 mg) i.v. 5 min before the end of surgery; transdermal placebo + 0.5 ml placebo i.v. as indicated above. Oxycodone i.m. and glycopyrrolate i.v. were given for premedication together with the test adhesive. Anaesthesia was induced with thiopental and maintained with nitrous oxide and oxygen, enflurane, vecuronium and fentanyl. Neostigmine and glycopyrrolate were administered for reversal. In the recovery room no differences in nausea or vomiting were observed between the groups. Sedation was significantly more marked (P less than 0.15-0.0001) after DHBP than after either TS or the given DHBP and 6% of those given the placebo (P less than 0.05). During the following 24 h nausea was reported more by the placebo patients (25) than by those on TS (20) or DHBP (15) (P less than 0.05). However, actual vomiting on the ward did not differ between the groups. Visual disturbances were more frequent after TS (P less than 0.01). We conclude that prophylactic transdermal scopolamine does not diminish postoperative emetic sequelae.
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