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  • Project Management Helps AmeriCares Deliver International Aid

    - by Sylvie MacKenzie, PMP
    Excerpt from PROFIT - ORACLE - by Alison Weiss Handle with Care Sound project management helps AmeriCares bring international aid to those in need. The stakes are always high for AmeriCares. On a mission to restore health and save lives during times of disaster, the nonprofit international relief and humanitarian aid organization delivers donated medicines, medical supplies, and humanitarian aid to people in the U.S. and around the globe. Founded in 1982 with the express mission of responding as quickly and efficiently as possible to help people in need, the Stamford, Connecticut-based AmeriCares has delivered more than US$10.5 billion in aid to 147 countries over the past three decades. Launch the Slideshow “It’s critically important to us that we steward all the donations and that the medical supplies and medicines get to people as quickly as possible with no loss,” says Kate Sears, senior vice president for finance and technology at AmeriCares. “Whether we’re shipping IV solutions to victims of cholera in Haiti or antibiotics to Somali famine victims, we need to get the medicines there sooner because it means more people will be helped and lives improved or even saved.” Ten years ago, the tracking systems used by AmeriCares associates were paper-based. In recent years, staff started using spreadsheets, but the tracking processes were not standardized between teams. “Every team was tracking completely different information,” says Megan McDermott, senior associate, Sub-Saharan Africa partnerships, at AmeriCares. “It was just a few key things. For example, we tracked the date a shipment was supposed to arrive and the date we got reports from our partner that a hospital received aid on their end.” While the data was accurate, much detail was being lost in the process. AmeriCares management knew it could do a better job of tracking this enterprise data and in 2011 took a significant step by implementing Oracle’s Primavera P6 Professional Project Management. “It’s a comprehensive solution that has helped us improve the monitoring and controlling processes. It has allowed us to do our distribution better,” says Sears. In addition, the implementation effort has been a change agent, helping AmeriCares leadership rethink project management across the entire organization. Initially, much of the focus was on standardizing processes, but staff members also learned the importance of thinking proactively to prevent possible problems and evaluating results to determine if goals and objectives are truly being met. Such data about process efficiency and overall results is critical not only to AmeriCares staff but also to the donors supporting the organization’s life-saving missions. Efficiency Saves Lives One of AmeriCares’ core operations is to gather product donations from the private sector, establish where the most-urgent needs are, and solicit monetary support to send the aid via ocean cargo or airlift to welfare- and health-oriented nongovernmental organizations, hospitals, health networks, and government ministries based in areas in need. In 2011 alone, AmeriCares sent more than 3,500 shipments to 95 countries in response to both ongoing humanitarian needs and more than two dozen emergencies, including deadly tornadoes and storms in the U.S. and the devastating tsunami in Japan. When it comes to nonprofits in general, donors want to know that the charitable organizations they support are using funds wisely. Typically, nonprofits are evaluated by donors in terms of efficiency, an area where AmeriCares has an excellent reputation: 98 percent of expenses go directly to supporting programs and less than 2 percent represent administrative and fundraising costs. Donors, however, should look at more than simple efficiency, says Peter York, senior partner and chief research and learning officer at TCC Group, a nonprofit consultancy headquartered in New York, New York. They should also look at whether organizations have the systems in place to sustain their missions and continue to thrive. An expert on nonprofit organizational management, York has spent years studying sustainable charitable organizations. He defines them as nonprofits that are able to achieve the ongoing financial support to stay relevant and continue doing core mission work. In his analysis of well over 2,500 larger nonprofits, York has found that many are not sustaining, and are actually scaling back in size. “One of the biggest challenges of nonprofit sustainability is the general public’s perception that every dollar donated has to go only to the delivery of service,” says York. “What our data shows is that there are some fundamental capacities that have to be there in order for organizations to sustain and grow.” York’s research highlights the importance of data-driven leadership at successful nonprofits. “You’ve got to have the tools, the systems, and the technologies to get objective information on what you do, the people you serve, and the results you’re achieving,” says York. “If leaders don’t have the knowledge and the data, they can’t make the strategic decisions about programs to take organizations to the next level.” Historically, AmeriCares associates have used time-tested and cost-effective strategies to ship and then track supplies from donation to delivery to their destinations in designated time frames. When disaster strikes, AmeriCares ships by air and generally pulls out all the stops to deliver the most urgently needed aid within the first few days and weeks. Then, as situations stabilize, AmeriCares turns to delivering sea containers for the postemergency and ongoing aid so often needed over the long term. According to McDermott, getting a shipment out the door is fairly complicated, requiring as many as five different AmeriCares teams collaborating together. The entire process can take months—from when products are received in the warehouse and deciding which recipients to allocate supplies to, to getting customs and governmental approvals in place, actually shipping products, and finally ensuring that the products are received in-country. Delivering that aid is no small affair. “Our volume exceeds half a billion dollars a year worth of donated medicines and medical supplies, so it’s a sizable logistical operation to bring these products in and get them out to the right place quickly to have the most impact,” says Sears. “We really pride ourselves on our controls and efficiencies.” Adding to that complexity is the fact that the longer it takes to deliver aid, the more dire the human need can be. Any time AmeriCares associates can shave off the complicated aid delivery process can translate into lives saved. “It’s really being able to track information consistently that will help us to see where are the bottlenecks and where can we work on improving our processes,” says McDermott. Setting a Standard Productivity and information management improvements were key objectives for AmeriCares when staff began the process of implementing Oracle’s Primavera solution. But before configuring the software, the staff needed to take the time to analyze the systems already in place. According to Greg Loop, manager of database systems at AmeriCares, the organization received guidance from several consultants, including Rich D’Addario, consulting project manager in the Primavera Global Business Unit at Oracle, who was instrumental in shepherding the critical requirements-gathering phase. D’Addario encouraged staff to begin documenting shipping processes by considering the order in which activities occur and which ones are dependent on others to get accomplished. This exercise helped everyone realize that to be more efficient, they needed to keep track of shipments in a more standard way. “The staff didn’t recognize formal project management methodology,” says D’Addario. “But they did understand what the most important things are and that if they go wrong, an entire project can go off course.” Before, if a boatload of supplies was being sent to Haiti and there was a problem somewhere, a lot of time was taken up finding out where the problem was—because staff was not tracking things in a standard way. As a result, even more time was needed to find possible solutions to the problem and alert recipients that the aid might be delayed. “For everyone to put on the project manager hat and standardize the way every single thing is done means that now the whole organization is on the same page as to what needs to occur from the time a hurricane hits Haiti and when a boat pulls in to unload supplies,” says D’Addario. With so much care taken to put a process foundation firmly in place, configuring the Primavera solution was actually quite simple. Specific templates were set up for different types of shipments, and dashboards were implemented to provide executives with clear overviews of every project in the system. AmeriCares’ Loop reports that system planning, refining, and testing, followed by writing up documentation and training, took approximately four months. The system went live in spring 2011 at AmeriCares’ Connecticut headquarters. While the nonprofit has an international presence, with warehouses in Europe and offices in Haiti, India, Japan, and Sri Lanka, most donated medicines come from U.S. entities and are shipped from the U.S. out to the rest of the world. In addition, all shipments are tracked from the U.S. office. AmeriCares doesn’t expect the Primavera system to take months off the shipping time, especially for sea containers. However, any time saved is still important because it will allow aid to be delivered to people more quickly at a lower overall cost. “If we can trim a day or two here or there, that can translate into lives that we’re saving, especially in emergency situations,” says Sears. A Cultural Change Beyond the measurable benefits that come with IT-driven process improvement, AmeriCares management is seeing a change in culture as a result of the Primavera project. One change has been treating every shipment of aid as a project, and everyone involved with facilitating shipments as a project manager. “This is a revolutionary concept for us,” says McDermott. “Before, we were used to thinking we were doing logistics—getting a container from point A to point B without looking at it as one project and really understanding what it meant to manage it.” AmeriCares staff is also happy to report that collaboration within the organization is much more efficient. When someone creates a shipment in the Primavera system, the same shared template is used, which means anyone can log in to the system to see the status of a shipment. Knowledgeable staff can access a shipment project to help troubleshoot a problem. Management can easily check the status of projects across the organization. “Dashboards are really useful,” says McDermott. “Instead of going into the details of each project, you can just see the high-level real-time information at a glance.” The new system is helping team members focus on proactively managing shipments rather than simply reacting when problems occur. For example, when a container is shipped, documents must be included for customs clearance. Now, the shipping template has built-in reminders to prompt team members to ask for copies of these documents from freight forwarders and to follow up with partners to discover if a shipment is on time. In the past, staff may not have worked on securing these documents until they’d been notified a shipment had arrived in-country. Another benefit of capturing and adopting best practices within the Primavera system is that staff training is easier. “Capturing the processes in documented steps and milestones allows us to teach new staff members how to do their jobs faster,” says Sears. “It provides them with the knowledge of their predecessors so they don’t have to keep reinventing the wheel.” With the Primavera system already generating positive results, management is eager to take advantage of advanced capabilities. Loop is working on integrating the company’s proprietary inventory management system with the Primavera system so that when logistics or warehousing operators input data, the information will automatically go into the Primavera system. In the past, this information had to be manually keyed into spreadsheets, often leading to errors. Mining Historical Data Another feature on the horizon for AmeriCares is utilizing Primavera P6 Professional Project Management reporting capabilities. As the system begins to include more historical data, management soon will be able to draw on this information to conduct analysis that has not been possible before and create customized reports. For example, at the beginning of the shipment process, staff will be able to use historical data to more accurately estimate how long the approval process should take for a particular country. This could help ensure that food and medicine with limited shelf lives do not get stuck in customs or used beyond their expiration dates. The historical data in the Primavera system will also help AmeriCares with better planning year to year. The nonprofit’s staff has always put together a plan at the beginning of the year, but this has been very challenging simply because it is impossible to predict disasters. Now, management will be able to look at historical data and see trends and statistics as they set current objectives and prepare for future need. In addition, this historical data will provide AmeriCares management with the ability to review year-end data and compare actual project results with goals set at the beginning of the year—to see if desired outcomes were achieved and if there are areas that need improvement. It’s this type of information that is so valuable to donors. And, according to York, project management software can play a critical role in generating the data to help nonprofits sustain and grow. “It is important to invest in systems to help replicate, expand, and deliver services,” says York. “Project management software can help because it encourages nonprofits to examine program or service changes and how to manage moving forward.” Sears believes that AmeriCares donors will support the return on investment the organization will achieve with the Primavera solution. “It won’t be financial returns, but rather how many more people we can help for a given dollar or how much more quickly we can respond to a need,” says Sears. “I think donors are receptive to such arguments.” And for AmeriCares, it is all about the future and increasing results. The project management environment currently may be quite simple, but IT staff plans to expand the complexity and functionality as the organization grows in its knowledge of project management and the goals it wants to achieve. “As we use the system over time, we’ll continue to refine our best practices and accumulate more data,” says Sears. “It will advance our ability to make better data-driven decisions.”

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  • Does Guest WiFi on an Access Point make any sense?

    - by uos??
    I have a Belkin WiFi Router which offers a feature of a secondary Guest Access WiFi network. Of course, the idea is that the Guest network doesn't have access to the computers/devices on the main network. I also have a Comcast-issues Cable Modem/Router device with mutliple wired ports, but no WiFi-capabilities. I prefer to only run one router/DHCP/NAT instead of both the Comcast Router and the Belkin Router, so I can disable the Routing functions of the Belkin and allow the Comcast Router to But if I disable the Routing functions of the Belkin device, the Guest WiFi network is still available. Is this configuration just as secure as when the Belkin acts as a Router? I guess the question comes down to this: Do Guest WiFi's provide security by 1) only allowing requests to IPs found in-front of the device, or do they work by 2) disallowing requests to IPs on the same subnet? 1) Would mean that Guest WiFi on an access point provides no benefit 2) Would mean that the Guest WiFi functionality can work even if the device is just an access point. Or maybe something else entirely?

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  • Is there a Windows 7 compatible IPSec VPN client that allows protocol and port specific rules?

    - by Sani Huttunen
    As the title says, I need to find a IPSec VPN client for Windows 7. On XP and Vista we've used SafeNet SoftRemote in which you can set up rules for specific protocols and ports. But SoftRemote isn't compatible with Windows 7. 172.xxx.xxx.1 TCP 1433 172.xxx.xxx.2 TCP 1433 172.xxx.xxx.10 ALL ... Since the VPN gateway is configured this way the client must mirror these settings. I've tried TheGreenBow, NCP Secure Entry, Cisco VPN Client and Shrew Soft VPN but none of these allows you to configure by protocol and port. Does anyone have any other suggestions? EDIT: Forgot to mention that agressive mode is also a requirement. --UPDATE-- I've got some news... I've managed to get SoftRemote to work on Windows 7 x64 through Windows XP Mode. After scouring all corners of the Internet for idéas I had enough information to construct a working solution. This solution will probably benefit other clients as well! You'll find a post here with detailed instructions of how I went about.

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  • CPU-adaptive compression

    - by liori
    Hello, Let assume I need to send some data from one computer to another, over a pretty fast network... for example standard 100Mbit connection (~10MB/s). My disk drives are standard HDD, so their speed is somewhere between 30MB/s and 100MB/s. So I guess that compressing the data on the fly could help. But... I don't want to be limited by CPU. If I choose an algorithm that is intensive on CPU, the transfer will actually go slower than without compression. This is difficult with compressors like GZIP and BZIP2 because you usually set the compression strength once for the whole transfer, and my data streams are sometimes easy, sometimes hard to compress--this makes the process suboptimal because sometimes I do not use full CPU, and sometimes the bandwidth is underutilized. Is there a compression program that would adapt to current CPU/bandwidth and hit the sweet spot so that the transfer will be optimal? Ideally for Linux, but I am still curious about all solutions. I'd love to see something compatible with GZIP/BZIP2 decompressors, but this is not necessary. So I'd like to optimize total transfer time, not simply amount of bytes to send. Also I don't need real time decompression... real time compression is enough. The destination host can process the data later in its spare time. I know this doesn't change much (compression is usually much more CPU-intensive than decompression), but if there's a solution that could use this fact, all the better. Each time I am transferring different data, and I really want to make these one-time transfers as quick as possible. So I won't benefit from getting multiple transfers faster due to stronger compression. Thanks,

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  • Four disks - RAID 10 or two mirrored pairs?

    - by ewwhite
    I have this discussion with developers quite often. The context is an application running in Linux that has a medium amount of disk I/O. The servers are HP ProLiant DL3x0 G6 with four disks of equal size @ 15k rpm, backed with a P410 controller and 512MB of battery or flash-based cache. There are two schools of thought here, and I wanted some feedback... 1). I'm of the mind that it makes sense to create an array containing all four disks set up in a RAID 10 (1+0) and partition as necessary. This gives the greatest headroom for growth, has the benefit of leveraging the higher spindle count and better fault-tolerance without degradation. 2). The developers think that it's better to have multiple RAID 1 pairs. One for the OS and one for the application data, citing that the spindle separation would reduce resource contention. However, this limits throughput by halving the number of drives and in this case, the OS doesn't really do much other than regular system logging. Additionally, the fact that we have the battery RAID cache and substantial RAM seems to negate the impact of disk latency... What are your thoughts?

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  • Can I autoregister my clients/servers in local DNS?

    - by Christian Wattengård
    Right now I have a W2k12 server at home that I run as a domain controller. This has the extra benefit of registering every "subordinate" computers name in it's DNS so that I don't have to go around remembering IP's all the time. (And it let's me easily run dhcp also on my servers). I need to rework my home network for several odd reasons, and in this new scenario there is no place for a big honking W2k12 server box. I have a RasPI, and I have other smallish linux boxen I can use. (In a worst case scenario I'll use my NUC, but then I'll be forced to use my home cinema's UPnP-client for media... The HORROR!!) Is it possible to set up a DNS-server-"appliance" that somehow autoregisters it's own hostname.. Scenario: Router (N66u) on 172.20.20.1. Runs DHCP on 172.20.20.100-200 range. Server [verdant] of a *nix flavor on 172.20.20.2 Laptop [speedy] of W8 flavor on DHCP assigned Laptop [canary] of W8 flavor on DHCP assigned Desktop [lianyu] of Ubunto flavor on DHCP assigned What I would like is that all of the above servers (except possibly the router) would be available on verdant.starling.lan and canary.starling.lan and so on. This is how it works right now (except the Ubuntu box... I haven't cracked that one yet) because Windows just does this for you.. I would also be able to do this without any manual labor on the server. When I tell my box it's name is smoak it should "immediately" be available as smoak.starling.lan without any extra configuration on my part. How can I do this in a Linux (Ubuntu) environment? (Bonus comment upvote for naming the naming scheme :P )

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  • Postfix spool on ext3 optimiziations in >=linux-2.6.34 days

    - by Luke404
    Given the very specific nature of the subject (we're not talking about mailboxes, just the spool; we're not talking about other filesystems, just ext3; and so on...) and the maturity of the softwares involved (linux kernel, ext3fs, postfix) I'd think there should be a more or less agreed on set of best practices to filesystem related tuning. I'm trying to get a roundup of them: data=journal became the default in recent kernels (somewhere around 2.6.30 IIRC) so we should be ok with that Wietse Venema says atime must be on, but Postfix documentation recommendsnoatime while talking about the Incoming Queue. Does that mean that postfix needs atime on just for some queue directories and will benefit from noatime on the others? can we use noatime if we just don't use ETRN? filesystem can be mounted nodev,noexec,nosuid - no* won't prevent you from setting attributes (postfix uses exec attr) they just won't have any effect (we don't run anything from the spool) the fsync() issue cited by Wietse and/or the chattr -S are probably linked to sync/async options of ext3fs but I do not understand them enough. Mouting the filesystem with async option is equivalent to chattr -R -S the whole fs? Seems like it will increase performance, but will that pose a risk of "loss of mail after a system crash" or is it really "safe on /var/spool/postfix" ? would you tune anything else on postfix-2.6.x to work better on ext3 or do you leave defaults everywhere? is there a "best" linux I/O scheduler for this kind of workload (namely CFQ or deadline?) or that's something that will vary too much based on hardware configuration? would you tune anything else in the filesystem or in the kernel? anything else? References: Postfix Performance here on SF Postfix documentation about the Incoming Queue Wietse Venema in Best file system on [email protected] here Postfix and ext3 on [email protected] here and there

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  • How to move my data from my old MacBook Pro to my new one?

    - by Tim Büthe
    I just purchased a new MacBook Pro and already got an 2008 model. I wonder how I move all my data over to the new one. My first idea was, to use my Time Machine backup and restore from it, which seems to be a good idea and should work just fine regarding to this link: http://blog.duncandavidson.com/2008/01/restoring-from-time-machine.html. But, since my current MacBook got older Software on it, like iLife '08 instead of iLife '09 I would have to upgrade this afterwards. Is this correct, or does Time Machine does some magic to exclude well known software? And is it possible to reinstall or upgrade iLife with the included installation DVDs? My second idea is, to just swap the hard drives instead of using the Time machine backup. If it is not too complicated to remove the hdd, this should be the fastest way. This also has the benefit, that the 2008er MacBook then contains a brand new installation and I don't have to remove all my stuff or reinstall Mac OS before I give it away. My question on that second idea would be: does snow leopard handle this stuff correctly? I reboot with the new hardware and all just works fine? So in a nutshell: What would you do: restore from backup or swap drives? And what about the new software?

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  • emule algorithm and how to get fast download speed.

    - by Benjamin
    Actually, I use amule in ubuntu. Because emule users are much more, I wrote emule in this title. But whatever emule or amule, it's okay. Both of them are very similar. I want to get fast-download speed as much as I can. But I don't understand emule(or amule)'s detail functions and algorithms. These are always very qurious to me. If I provide higher upload-speed or more valuable files to other people, can I get benefit?(My download speed) Is serverlist important? Does it cause my download-speed? I captured a image for my amule. Please explain these columns and let me know your tips for getting fast speed. What does 8/9+23 mean in the Source column? What does 294/300(1) mean in the Source column? What does QR:608(0) mean in the Priority? What do I do for getting fast download speed as much as I can get? You can also explain other columns.

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  • Virtual Machine Network Architecture, Isolating Public and Private Networks

    - by Mark
    I'm looking for some insight into best practices for network traffic isolation within a virtual environment, specifically under VMWARE ESXi. Currently I have (in testing) 1 hardware server running ESXi but i expect to expand this to multiple pieces of hardware. The current setup is as follows: 1 pfsense VM, this VM accepts all outside (WAN/internet) traffic and performs firewall/port forwarding/NAT functionality. I have multiple public IP addresses sent to the this VM that are used for access to individual servers (via per incoming IP port forwarding rules). This VM is attached to the private (virtual) network that all other VMs are on. It also manages a VPN link into the private network with some access restrictions. This isn't the perimeter firewall but rather the firewall for this virtual pool only. I have 3 VMs that communicate with each other, as well as have some public access requirements: 1 LAMP server running an eCommerce site, public internet accessible 1 accounting server, access via windows server 2008 RDS services for remote access by users 1 inventory/warehouse management server, VPN to client terminals in warehouses These servers constantly talk with each other for data synchronization. Currently all the servers are on the same subnet/virtual network and connected to the internet through the pfsense VM. The pfsense firewall uses port forwarding and NAT to allow outside access to the servers for services and for server access to the internet. My main question is this: Is there a security benefit to adding a second virtual network adapter to each server and controlling traffic such that all server to server communication is on one separate virtual network, while any access to the outside world is routed through the other network adapter, through the firewall, and on the the internet. This is the type of architecture i would use if these were all physical servers, but i'm unsure if the networks being virtual changes the way i should approach locking down this system. Thank you for any thoughts or direction to any appropriate literature.

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  • Windows memory logged on vs logged off

    - by Adi
    Let's say I power on my fresh installed Windows 7 x64 machine. After Windows boots up, there are a bunch of services being started in the background that start allocating memory. Then I enter my user/pass and Windows logs me in. Let's supose I don't do anythig else (I don't explicitely start any application) and I don't have any other app installed by me. So it's fresh install of my machine. My question is: how much memory is needed for all the UI & other stuff? Is it a good indicator to look into task manager and check all the processes started under my user name and sum up all the memory consumed by those processes to get the total amount of memory I am consuming just to stay logged on? Basically this is my question: how much memory is needed just to stay logged on? Now, if log off would all the memory be released back to the system so that the background services can benefit of? Also, I assume that there might be a different discussion for each Windows flavors (?)

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  • C#/.NET Little Wonders: Interlocked CompareExchange()

    - by James Michael Hare
    Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. Two posts ago, I discussed the Interlocked Add(), Increment(), and Decrement() methods (here) for adding and subtracting values in a thread-safe, lightweight manner.  Then, last post I talked about the Interlocked Read() and Exchange() methods (here) for safely and efficiently reading and setting 32 or 64 bit values (or references).  This week, we’ll round out the discussion by talking about the Interlocked CompareExchange() method and how it can be put to use to exchange a value if the current value is what you expected it to be. Dirty reads can lead to bad results Many of the uses of Interlocked that we’ve explored so far have centered around either reading, setting, or adding values.  But what happens if you want to do something more complex such as setting a value based on the previous value in some manner? Perhaps you were creating an application that reads a current balance, applies a deposit, and then saves the new modified balance, where of course you’d want that to happen atomically.  If you read the balance, then go to save the new balance and between that time the previous balance has already changed, you’ll have an issue!  Think about it, if we read the current balance as $400, and we are applying a new deposit of $50.75, but meanwhile someone else deposits $200 and sets the total to $600, but then we write a total of $450.75 we’ve lost $200! Now, certainly for int and long values we can use Interlocked.Add() to handles these cases, and it works well for that.  But what if we want to work with doubles, for example?  Let’s say we wanted to add the numbers from 0 to 99,999 in parallel.  We could do this by spawning several parallel tasks to continuously add to a total: 1: double total = 0; 2:  3: Parallel.For(0, 10000, next => 4: { 5: total += next; 6: }); Were this run on one thread using a standard for loop, we’d expect an answer of 4,999,950,000 (the sum of all numbers from 0 to 99,999).  But when we run this in parallel as written above, we’ll likely get something far off.  The result of one of my runs, for example, was 1,281,880,740.  That is way off!  If this were banking software we’d be in big trouble with our clients.  So what happened?  The += operator is not atomic, it will read in the current value, add the result, then store it back into the total.  At any point in all of this another thread could read a “dirty” current total and accidentally “skip” our add.   So, to clean this up, we could use a lock to guarantee concurrency: 1: double total = 0.0; 2: object locker = new object(); 3:  4: Parallel.For(0, count, next => 5: { 6: lock (locker) 7: { 8: total += next; 9: } 10: }); Which will give us the correct result of 4,999,950,000.  One thing to note is that locking can be heavy, especially if the operation being locked over is trivial, or the life of the lock is a high percentage of the work being performed concurrently.  In the case above, the lock consumes pretty much all of the time of each parallel task – and the task being locked on is relatively trivial. Now, let me put in a disclaimer here before we go further: For most uses, lock is more than sufficient for your needs, and is often the simplest solution!    So, if lock is sufficient for most needs, why would we ever consider another solution?  The problem with locking is that it can suspend execution of your thread while it waits for the signal that the lock is free.  Moreover, if the operation being locked over is trivial, the lock can add a very high level of overhead.  This is why things like Interlocked.Increment() perform so well, instead of locking just to perform an increment, we perform the increment with an atomic, lockless method. As with all things performance related, it’s important to profile before jumping to the conclusion that you should optimize everything in your path.  If your profiling shows that locking is causing a high level of waiting in your application, then it’s time to consider lighter alternatives such as Interlocked. CompareExchange() – Exchange existing value if equal some value So let’s look at how we could use CompareExchange() to solve our problem above.  The general syntax of CompareExchange() is: T CompareExchange<T>(ref T location, T newValue, T expectedValue) If the value in location == expectedValue, then newValue is exchanged.  Either way, the value in location (before exchange) is returned. Actually, CompareExchange() is not one method, but a family of overloaded methods that can take int, long, float, double, pointers, or references.  It cannot take other value types (that is, can’t CompareExchange() two DateTime instances directly).  Also keep in mind that the version that takes any reference type (the generic overload) only checks for reference equality, it does not call any overridden Equals(). So how does this help us?  Well, we can grab the current total, and exchange the new value if total hasn’t changed.  This would look like this: 1: // grab the snapshot 2: double current = total; 3:  4: // if the total hasn’t changed since I grabbed the snapshot, then 5: // set it to the new total 6: Interlocked.CompareExchange(ref total, current + next, current); So what the code above says is: if the amount in total (1st arg) is the same as the amount in current (3rd arg), then set total to current + next (2nd arg).  This check and exchange pair is atomic (and thus thread-safe). This works if total is the same as our snapshot in current, but the problem, is what happens if they aren’t the same?  Well, we know that in either case we will get the previous value of total (before the exchange), back as a result.  Thus, we can test this against our snapshot to see if it was the value we expected: 1: // if the value returned is != current, then our snapshot must be out of date 2: // which means we didn't (and shouldn't) apply current + next 3: if (Interlocked.CompareExchange(ref total, current + next, current) != current) 4: { 5: // ooops, total was not equal to our snapshot in current, what should we do??? 6: } So what do we do if we fail?  That’s up to you and the problem you are trying to solve.  It’s possible you would decide to abort the whole transaction, or perhaps do a lightweight spin and try again.  Let’s try that: 1: double current = total; 2:  3: // make first attempt... 4: if (Interlocked.CompareExchange(ref total, current + i, current) != current) 5: { 6: // if we fail, go into a spin wait, spin, and try again until succeed 7: var spinner = new SpinWait(); 8:  9: do 10: { 11: spinner.SpinOnce(); 12: current = total; 13: } 14: while (Interlocked.CompareExchange(ref total, current + i, current) != current); 15: } 16:  This is not trivial code, but it illustrates a possible use of CompareExchange().  What we are doing is first checking to see if we succeed on the first try, and if so great!  If not, we create a SpinWait and then repeat the process of SpinOnce(), grab a fresh snapshot, and repeat until CompareExchnage() succeeds.  You may wonder why not a simple do-while here, and the reason it’s more efficient to only create the SpinWait until we absolutely know we need one, for optimal efficiency. Though not as simple (or maintainable) as a simple lock, this will perform better in many situations.  Comparing an unlocked (and wrong) version, a version using lock, and the Interlocked of the code, we get the following average times for multiple iterations of adding the sum of 100,000 numbers: 1: Unlocked money average time: 2.1 ms 2: Locked money average time: 5.1 ms 3: Interlocked money average time: 3 ms So the Interlocked.CompareExchange(), while heavier to code, came in lighter than the lock, offering a good compromise of safety and performance when we need to reduce contention. CompareExchange() - it’s not just for adding stuff… So that was one simple use of CompareExchange() in the context of adding double values -- which meant we couldn’t have used the simpler Interlocked.Add() -- but it has other uses as well. If you think about it, this really works anytime you want to create something new based on a current value without using a full lock.  For example, you could use it to create a simple lazy instantiation implementation.  In this case, we want to set the lazy instance only if the previous value was null: 1: public static class Lazy<T> where T : class, new() 2: { 3: private static T _instance; 4:  5: public static T Instance 6: { 7: get 8: { 9: // if current is null, we need to create new instance 10: if (_instance == null) 11: { 12: // attempt create, it will only set if previous was null 13: Interlocked.CompareExchange(ref _instance, new T(), (T)null); 14: } 15:  16: return _instance; 17: } 18: } 19: } So, if _instance == null, this will create a new T() and attempt to exchange it with _instance.  If _instance is not null, then it does nothing and we discard the new T() we created. This is a way to create lazy instances of a type where we are more concerned about locking overhead than creating an accidental duplicate which is not used.  In fact, the BCL implementation of Lazy<T> offers a similar thread-safety choice for Publication thread safety, where it will not guarantee only one instance was created, but it will guarantee that all readers get the same instance.  Another possible use would be in concurrent collections.  Let’s say, for example, that you are creating your own brand new super stack that uses a linked list paradigm and is “lock free”.  We could use Interlocked.CompareExchange() to be able to do a lockless Push() which could be more efficient in multi-threaded applications where several threads are pushing and popping on the stack concurrently. Yes, there are already concurrent collections in the BCL (in .NET 4.0 as part of the TPL), but it’s a fun exercise!  So let’s assume we have a node like this: 1: public sealed class Node<T> 2: { 3: // the data for this node 4: public T Data { get; set; } 5:  6: // the link to the next instance 7: internal Node<T> Next { get; set; } 8: } Then, perhaps, our stack’s Push() operation might look something like: 1: public sealed class SuperStack<T> 2: { 3: private volatile T _head; 4:  5: public void Push(T value) 6: { 7: var newNode = new Node<int> { Data = value, Next = _head }; 8:  9: if (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next) 10: { 11: var spinner = new SpinWait(); 12:  13: do 14: { 15: spinner.SpinOnce(); 16: newNode.Next = _head; 17: } 18: while (Interlocked.CompareExchange(ref _head, newNode, newNode.Next) != newNode.Next); 19: } 20: } 21:  22: // ... 23: } Notice a similar paradigm here as with adding our doubles before.  What we are doing is creating the new Node with the data to push, and with a Next value being the original node referenced by _head.  This will create our stack behavior (LIFO – Last In, First Out).  Now, we have to set _head to now refer to the newNode, but we must first make sure it hasn’t changed! So we check to see if _head has the same value we saved in our snapshot as newNode.Next, and if so, we set _head to newNode.  This is all done atomically, and the result is _head’s original value, as long as the original value was what we assumed it was with newNode.Next, then we are good and we set it without a lock!  If not, we SpinWait and try again. Once again, this is much lighter than locking in highly parallelized code with lots of contention.  If I compare the method above with a similar class using lock, I get the following results for pushing 100,000 items: 1: Locked SuperStack average time: 6 ms 2: Interlocked SuperStack average time: 4.5 ms So, once again, we can get more efficient than a lock, though there is the cost of added code complexity.  Fortunately for you, most of the concurrent collection you’d ever need are already created for you in the System.Collections.Concurrent (here) namespace – for more information, see my Little Wonders – The Concurent Collections Part 1 (here), Part 2 (here), and Part 3 (here). Summary We’ve seen before how the Interlocked class can be used to safely and efficiently add, increment, decrement, read, and exchange values in a multi-threaded environment.  In addition to these, Interlocked CompareExchange() can be used to perform more complex logic without the need of a lock when lock contention is a concern. The added efficiency, though, comes at the cost of more complex code.  As such, the standard lock is often sufficient for most thread-safety needs.  But if profiling indicates you spend a lot of time waiting for locks, or if you just need a lock for something simple such as an increment, decrement, read, exchange, etc., then consider using the Interlocked class’s methods to reduce wait. Technorati Tags: C#,CSharp,.NET,Little Wonders,Interlocked,CompareExchange,threading,concurrency

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  • How does the Windows RENAME command interpret wildcards?

    - by dbenham
    How does the Windows RENAME (REN) command interpret wildcards? The built in HELP facility is of no help - it doesn't address wildcards at all. The Microsoft technet XP online help isn't much better. Here is all it has to say regarding wildcards: "You can use wildcards (* and ?) in either file name parameter. If you use wildcards in filename2, the characters represented by the wildcards will be identical to the corresponding characters in filename1." Not much help - there are many ways that statement can be interpretted. I've managed to successfully use wildcards in the filename2 parameter on some occasions, but it has always been trial and error. I haven't been able to anticipate what works and what doesn't. Frequently I've had to resort to writing a small batch script with a FOR loop that parses each name so that I can build each new name as needed. Not very convenient. If I knew the rules for how wildcards are processed then I figure I could use the RENAME command more effectively without having to resort to batch as often. Of course knowing the rules would also benefit batch development. (Yes - this is a case where I am posting a paired question and answer. I got tired of not knowing the rules and decided to experiment on my own. I figure many others may be interested in what I discovered)

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  • Can I use @import to import Kod's default style sheet into my own?

    - by Thomas Upton
    I understand that Kod is being actively developed and is prone to drastic changes in any area. I would like to modify some small things (like font face and size or certain colors) while still being able to benefit from any changes or updates to the default Kod stylesheet. I thought that I would be able to @import the default stylesheet into my own to achieve this. This is what ~/.kod/custom.css would look like, @import url("file:///Applications/Kod.app/Contents/Resources/style/default.css"); /* Change the default font face and color. */ body { font-family: Menlo, monospace; color: #efefef; } This stylesheet was set with the following defaults command, per the comments at the top of Kod's default CSS file: defaults write se.hunch.kod style/url ~/.kod/custom.css Unfortunately, this didn't work. When I first tried to reload the style, Kod crashed. It opened fine again, but the @import statement wasn't working, and Kod crashed every time I saved the custom.css file. Am I doing something wrong? Did I write my @import statement wrong? Is that not how @import is supposed to work? Did I miss some sort of documentation or Kod Google Groups post that mentions that Kod explicitly disallows this?

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  • Value of Itanium or Sparc over x86_64 for Oracle Deployment

    - by Antitribu
    We are looking at a new environment to run our Oracle Database running on SUSE (potentially migrating to RedHat). Our database is approximately 100GB and performs adequately on our current hardware (x86_64) with approximately 6GB of ram allocated to it. We are growing quickly however and will require more performance shortly. Given the cost of Oracle licenses we would like to maximize the value from each license by choosing the most appropriate CPU to run the software on. The questions are: Are there substantial benefits to looking at Itanium or Sparc hardware, are there any drawbacks? Is there a point where one starts to scale out better? What are the long term support options for Itanium? Given the dominance of x86 would it be safer long term to stick with x86? On average what would be the performance benefit of implementing an Oracle database on Itanium or Sparc over x86_64? Is this an issue at all or will other factors (IO/RAM) cap out first? If anyone can point me towards some solid documentation on comparisons between the platforms that provides good case analysis of when to choose which I'm more than happy to accept that as an answer. Edit:- Added Sparc as an Option as it was previously not considered however with the recent Oracle Sun aquisition seems very relevant.

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  • SQL Server performance on VSphere 4.0

    - by Charles
    We are having a performance issue that we cannot explain with our VMWare environment and I am hoping someone here may be able to help. We have a web application that uses a databases backend. We have an SQL 2005 Cluster setup on Windows 2003 R2 between a physical node and a virtual node. Both physical servers are identical 2950's with 2x Xeaon x5460 Quad Core CPUs and 64GB of memory, 16GB allocated to the OS. We are utilizing an iSCSI San for all cluster disks. The problem is this, when utilizing the application under a repeated stress testing that adds CPUs to the cluster nodes, the Physical node scales from 1 pCPU to 8 pCPUs, meaning we see continued performance increases. When testing the node running Vsphere, we have the expected 12% performance hit for being virtual but we still scale from 1 vCPU to 4 vCPUs like the physical but beyond this performance drops off, by the time we get to 8 vCPUs we are seeing performance numbers worse than at 4 vCPUs. Again, both nodes are configured identically in terms of hardware, Guest OS, SQL Configurations etc and there is no traffic other than the testing on the system. There are no other VMs on the virtual server so there should be no competition for resources. We have contacted VMWare for help but they have not really been any suggesting things like setting SQL Processor Affinity which, while being helpful would have the same net effect on each box and should not change our results in the least. We have looked at all of VMWare's SQL Tuning guides with regards to VSphere with no benefit, please help!

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  • Router vs switch in a LAN [closed]

    - by servernewbie
    If I have a LAN and and connect it with a switch, I understand it uses a CAM table to route packets in layer 2 (by saving mac to port relations). So far all good. However, when using a router for a LAN (ONLY for a LAN, not to connect it to "the outside" WAN/internet/etc) I get a bit confused as to how it internally processes packets. I would first split this into two router scenarios: Router with buit-in switch In this scenario, I would expect that it will act exactly as a switch with a CAM table internally. This would probably benefit a bit in speed (guessing here?) compared to the next option. Router without built-in switch Here is where I get confused. If hostA wants to send a packet to hostB, it will ARP to find hostB's MAC address and send it there. Now, if we had a switch (above scenario) this would be easy. But how does it work now in a router WITHOUT a switch? If I would guess, hostA would send an Ethernet frame with hostB's MAC address to the line. The router would fetch the packet (even though the router has another MAC address, it would still fetch this packet even if it only contains hostB's MAC address). It would strip the Ethernet frame header and check the IP, and then check its own internal ARP table again for the MAC address. Now, this would seem like a waste of resources compared to a router with a built-in switch. But maybe it does not work like that at all. Does it also contain a CAM table? If that would be true, what would then the difference between these two routers really be?

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  • When should NTPd broadcast/broadcastclient be used instead of client/server or peer modes?

    - by Luke404
    The NTP deamon if often used in its simplest mode, which is client/server: you specify one or more server directives in your ntp.conf and your clients will use those servers. In addition to that, when you run your own NTP servers, it is good practice to peer them together, so if one of them looses connectivity to its upstream servers, it will get time from its peers. But NTPd can also work with broadcast and/or multicast distribution of time data, with the documentation stating: broadcast and multicast modes are intended for configurations involving one or a few servers and a possibly very large client population The documentation also says elsewhere: It is possible and frequently useful to configure a host as both broadcast client and broadcast server. A number of hosts configured this way and sharing a common broadcast address will automatically organize themselves in an optimum configuration based on stratum and synchronization distance. I can see one obvious administrative benefit: you don't have to manually specify and update your list of NTP servers in the clients ntp.conf, so to me it looks tempting to use broadcast mode even for a small client population (say 5+ clients with 3~4 servers). I expect network traffic to be a little higher with broadcasts instead of client/server associations, but given the usual gigabit ethernet LAN the impact should be negligible unless you have a very very large number of hosts in the same broadcast domain. At the end of the day, when should broadcast mode be used or avoided? Are there pros and cons I haven't seen?

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  • Best grep-like tool

    - by e-satis
    I do in file search a lot, and used to love grep. Then I learn the existence of egrep, so I switched to benefit from the advanced regexp. Then I discovered the Eclipse search tool. Much easier to use that grep. Then I found ack : fast, easy, powerful. And now I use grin, which is smooth for pythonistas. I know there is also a couple of this kind of tools with a GUI. So what tool do you use, and why do you think it's the best. Practical features generally are : fast to fire and use; speedy processing; automatically ignore useless files; colored output; output lines, filename, context; allow complex regexp; allow a custom filtering and ouput; GUI + command line intergation; let you open an editor from the result set. There are some related posts on SO : http://stackoverflow.com/questions/87350/what-are-good-grep-tool-for-windows http://stackoverflow.com/questions/981601/colorized-grep-viewing-the-entire-file-with-highlighting http://stackoverflow.com/questions/1028107/is-there-some-unix-util-that-will-allow-me-to-grep-multiple-files-with-little-type http://stackoverflow.com/questions/1027906/unix-find-grep-syntax-vs-awk

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  • Limiting bandwith on an Windows 7 machine

    - by Mihai Damian
    I need to limit the bandwidth on my Windows 7 x64 machine. In the past (on XP) I've been able to use NetLimiter for similar tasks. However for some reason I can't get it to work anymore. For lower limits the bandwidth tests are able to exceed the limit by 10-50%; higher limits seem to be ignored completely and the bandwidth tests report download speeds of over 10 times the speed I set. I'm using speedtest.net and some similar service from my ISP for these tests. Anyway, I don't necessarily need a program as complex as NetLimiter since I only need to throttle my machine's bandwidth, not a specific program's. In case you are wondering why in the world I'd want to cripple my Internet speed, there is a funny story behind this. Long story short, my modem gets random disconnects. Tech support comes in, says my Internet speed is abnormally high and I must be using some tools to somehow make it go faster than it's supposed to and this messes up my modem. I check the connection with another computer and it seems that my PC is the only one in my network that gets abnormal speeds. I reinstall my OS, speed looks normal at first, after I install the batch of 50 or so updates, it goes back to abnormally high speeds and the disconnect problems are not solved. Now I don't have a clue if the explanation the tech team gave me was just a strategy to lay the blame on someone else, but I was trying to give them the benefit of the doubt and see what happens if I really reduce my speed to their specification. Any help appreciated.

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  • Using wildcard domains to serve images without http blocking

    - by iopener
    I read that browsers sometimes block waiting for multiple images from the same host, and I'm trying to do everything I can to speed up page load times. One caveat: I need to serve files over HTTPS. Any opinions about whether this is feasible: Setup a wildcard cert for *.domain.com. Whenever I need an image, generate an number based on a hash mod 5 of the filename, and append it to an 'img' subdomain (eg img1.domain.com, img4.domain.com, img3.domain.com, etc.); the hash will make any filename always use the same subdomain, and therefore the browser should be able to cache the images Configure a dynamic virtualhost record to point all img#. subdomains to /var/www/img I am looking for feedback about this plan. My concerns are: Will I get warnings when my page has https:// links to multiple subdomains? Is the dynamic virtualhost record I'm talking about even possible? Considering the amount of processing this would require, is it likely to even produce any kind of overall benefit? I'm probably averaging a half-dozen images per page, with only half being changed on each page refresh. Thanks in advance for you feedback.

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  • Recommended drive encryption solution

    - by Chris Driver
    Hello, I will soon be purchasing a number of laptops running Windows 7 for our mobile staff. Due to the nature of our business I will need drive encryption. Windows BitLocker seems the obvious choice, but it looks like I need to purchase either Windows 7 Enterprise or Ultimate editions to get it. Can anyone offer suggestions on the best course of action: a) Use BitLocker, bite the bullet and pay to upgrade to Enterprise/Ultimate b) Pay for another 3rd party drive encryption product that is cheaper (suggestions appreciated) c) Use a free drive encryption product such as TrueCrypt Ideally I am also interested in 'real world' experience from people who are using drive encryption software and any pitfalls to look out for. Many thanks in advance... UPDATE Decided to go with TrueCrypt for the following reasons: a) The product has a good track record b) I am not managing a large quantity of laptops so integration with Active Directory, Management consoles etc is not a huge benefit c) Although eks did make a good point about Evil Maid (EM) attacks, our data is not that desirable to consider it a major factor d) The cost (free) is a big plus but not the primary motivator The next problem I face is imaging (Acronis/Ghost/..) encrypted drives will not work unless I perform sector-by-sector imaging. That means an 80Gb encrypted partition creates an 80Gb image file :(

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  • Serving images from another hostname vs Apache overload for the rewrites

    - by luison
    We are trying to improve further the speed of some sites with older HTML in order as well to obtain better SEO results. We have now applied some minify measures, combined html, css etc. We use a small virtualized infrastructure and we've always wanted to use a light + standar http server configuration so the first one can serve images and static contents vs the other one php, rewrites, etc. We can easily do that now with a VM using the same files and conf of vhosts (bind mounts) on apache but with hardly any modules loaded. This means the light httpd will have smaller fingerprint that would allow us to serve more and quicker, have more minSpareServer running, etc. So, as browsers benefit from loading static content from different hostnames as well, we've thought about building a rewrite rule on our main server (main.com) to "redirect" all images and css *.jpg, *.gif, *.css etc to the same at say cdn.main.com thus the browser being able to have more connections. The question is, assuming we have a very complex rewrite ruleset already (we manually manipulate many old URLs for SEO) will it be worth? I mean will the additional load of main's apache to have to redirect main.com/image.jpg (I understand we'll have to do a 301) to cdn.main.com/image.jpg + then cdn.main.com having to serve it, be larger than the gain we would be archiving on the browser? Could the excess of 301s of all images on a page be penalized by google? How do large companies work this out, does the original code already include images linked from the cdn with absolute paths?

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  • Can I autoregister my servers hostname in my local DNS? [on hold]

    - by Christian Wattengård
    We have evaluated a W2k12 server as a domain controller at work. This has the extra benefit of registering every "subordinate" computers name in it's DNS so that I don't have to go around remembering IP's all the time. (And it let's me easily run dhcp also on my "pop-up" dev-servers). We need to rework our work network for several odd reasons, and in this new scenario there was no money for an extra Windows 2012 license. We have at our disposal several old boxes that run linux quite well. Is it possible to set up a DNS-server-"appliance" that somehow autoregisters it's own hostname.. Scenario: Router (N66u) on 172.20.20.1. Runs DHCP on 172.20.20.100-200 range. Server [verdant] of a *nix flavor on 172.20.20.2 Laptop [speedy] of W8 flavor on DHCP assigned Laptop [canary] of W8 flavor on DHCP assigned Desktop [lianyu] of Ubuntu flavor on DHCP assigned What I would like is that all of the above servers (except possibly the router) would be available on verdant.starling.lan and canary.starling.lan and so on. This is how it works right now (except the Ubuntu box... I haven't cracked that one yet) because Windows just does this for you.. I would also be able to do this without any manual labor on the server. When I tell my box it's name is smoak it should "immediately" be available as smoak.starling.lan without any extra configuration on my part. How can I do this in a Linux (Ubuntu) environment?

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  • SSD for swap on Ubuntu server

    - by grs
    Currently I am reading SSD reviews and I wonder how much exactly I will benefit if I move the 24 GB swap from 7200rpm HDD to SSD. Does anyone implemented swap space on SSD? Is this generally good idea? On a side note: I read that ext4 has much better performance if the journal is on SSD. Anyone with such a setup? Thanks! Edit: Here I will answer the questions posted: Occasionally, relatively rare I am hitting the swap. I know what the swap is for and that is better to get more RAM. When the server begins to swap its performance degrades (not a surprise). The idea is if I have few memory hungry processes running, to improve the overall system performance at that time, using SSD for swap, instead of slower rotational media. At the end - I want to be able to login faster and check the server state during swapping, instead of waiting on the login prompt. And of what I see SSD is cheaper per GB than RAM. Would I have better server performance during swapping (as rare it is) using SSD compared to HDD? Where 10k or 15k rpm HDDs would rate in this scenario? Thank you all for your quick and prompt answers!

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