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• What is the cheapest non-colocation way to serve about 10 static files at a rate of 100 megabits per

  - by Mark Maunder

  I've looked at Amazon S3 and it costs roughly $4746 per month for 100 megabits/s (which translates into 31,640 Gigabytes of data transferred. That's at a rate of $0.15 per gig.) I haven't found a cheaper "cloud" option. I'm curious if there's any other cloud hosting option out there cheaper than S3. Uptime is not an issue because I can build failover for most things into the browser. e.g. I can use javascript to say "if the image didn't load then go to this other URL instead." FYI I'm currently using a colocation facility which is about 30% cheaper than S3 and I'm familiar with colo prices - so this question is really about "cloud" services and by that I mean services where I don't have to worry about the infrastructure.

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• How to Set Up a MongoDB NoSQL Cluster Using Oracle Solaris Zones

  - by Orgad Kimchi

  This article starts with a brief overview of MongoDB and follows with an example of setting up a MongoDB three nodes cluster using Oracle Solaris Zones. The following are benefits of using Oracle Solaris for a MongoDB cluster: • You can add new MongoDB hosts to the cluster in minutes instead of hours using the zone cloning feature. Using Oracle Solaris Zones, you can easily scale out your MongoDB cluster. • In case there is a user error or software error, the Service Management Facility ensures the high availability of each cluster member and ensures that MongoDB replication failover will occur only as a last resort. • You can discover performance issues in minutes versus days by using DTrace, which provides increased operating system observability. DTrace provides a holistic performance overview of the operating system and allows deep performance analysis through cooperation with the built-in MongoDB tools. • ZFS built-in compression provides optimized disk I/O utilization for better I/O performance. In the example presented in this article, all the MongoDB cluster building blocks will be installed using the Oracle Solaris Zones, Service Management Facility, ZFS, and network virtualization technologies. Figure 1 shows the architecture:

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• Resilient Linux Mail Server Setup

  - by Coops

  How would people design a resilient mail server setup with Linux? On an application level what the system needs to provide is both an incoming and outgoing mail service (i.e. SMTP & IMAP), along with filtering and archive storage (the archive part isn't critical yet, so we'll look at this later probably). What is required on top of this is a resilient system, i.e. one which will handle individual server failures without interrupting service. As such I would term this a High Availability mail system. This is in contrast to a High Performance mail setup, as in our case the volume of mail being handled isn't the important factor, it's simply that it stays online. Having not approached this problem before, the first thing I thought of was a clustered file system (gfs/gluster/etc), combined with heartbeat to failover a floating IP to another box in the case of a server failure. Combined with postfix & dovecot does this sound feasible to people?

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• RDS Replication across regions

  - by Bryan Migliorisi

  We are using Amazon AWS for our web services but given the recent instabilities in their infrastructure, we are trying to figure out how to run our application across multiple regions for additional redundancy. Ideally, we would run our entire app in a active-active configuration in multiple regions but our main concern is that we are using RDS, which I understand cannot replicate across regions. One possible solution (though we have not tried or proven it would work) would be to do mysqldump or EBS snapshots every hour or so but this would mean that we would be forced to run in an active-passive configuration. Our data would be at most an hour behind. This carries its own issues around data synchronization when we failover and the master comes back up, so its not the best solution. Are there any proven solutions for replicating RDS across regions?

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• Highly Available Web Application (LAMP)

  - by Anthony Rizzo

  I work for a small company who provides a web application for thousands of users. Earlier this year they had one server hosted one company. We recently acquired another server in a different location with the hopes of one day making this a redundant failover machine. I understand what to do with the mysql replication, I plan on using a master-master replication setup, and rsync to sync the scripts and files, however I am at a stand still about how to configure the fail-over. Ideally I would like the two machines to accept requests, like a round robin dns, however if one machine goes down I do not want requests to go that machine. All of the solutions I am come across assumes high availability of servers in the same location, these servers are in two completely different locations with different public ip address. Any help would be great. Thanks

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• Tipps & Tricks rund um CRSCTL

  - by Sebastian Solbach (DBA Community)

  Egal ob Single Instanz oder für Real Applikation Cluster Datenbanken die Grid Infrastruktur findet man bei immer mehr Systemen im Einsatz. Das liegt sowohl an der vereinfachten Überwachungstätigkeiten für die Oracle Datenbank, Listener und ASM Instanz, als auch an einigen weiterführenden Features, wie der einfachen Service Verwaltung für Single Instanz, DataGuard und/oder RAC. Dabei kommen insbesondere den Cluster Ready Services (CRS), einem Bestandteil der Clusterware Komponente der Grid Infrastruktur, eine wichtige Bedeutung zu, da diese intern alle Ressourcen steuert. Ressourcen können hierbei natürlich nicht nur die Oracle Prozesse (Datenbank, Listener, Virtuelle IP Adressen etc.) sein, sondern auch eigene Applikationen, die unter die Überwachung der Grid Infrastruktur resp. Clusterware gestellt werden. Dies kann von simplen Neustartanforderungen im Single Server Betrieb bis zu klassischen Failover Szenarien in Clusterumgebungen reichen. Diesem Aspekt trägt auch die Tatsache Rechnung, dass es seit einiger Zeit generische Applikations-Agenten (Siebel, Tomcat, GoldenGate, Apache, ...) für die Clusterware gibt und eine abgespeckte GI Installation auf der Oracle eigenen Middleware Hardware (Exalogic) läuft, um die Prozesse zu überwachen. Diese Cluster Ready Services werden vom Befehl "crsctl" gesteuert. Deshalb lohnt es sich dieses Utility mal genauer anzuschauen, zumal es einige Feinheiten enthält, die nicht direkt aus der Dokumentation bzw. Hilfe des Tools ersichtlich sind.

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• Dedicated Servers: Is one better then two for LAMP pseudo HA setup? [closed]

  - by bikedorkseattle

  Possible Duplicate: How to find web hosting that meets my requirements? I know there are zillions of commentary about hosting out there, but I haven't read much about this. Our current well known host is having too many problems, the hardware we are on it subpar, and I'm ready to leave. A day of downtime can cost as much as our monthly hosting bill. A month of bad performance is just killing us right now, user and google wise. I'm wondering about running two dedicated boxes for LAMP, one running as the primary Nginx/Apache (proxy pass), and the other as the MySQL box. Running a single box scares the bejesus out of me because who knows how long it will take anyone to fix a raid card or whatever. The idea is to set this up using some sort of failover system using pacemaker and heartbeat. If one server goes down the other can take over for the other running both web and db. There are some good articles over at Linode about this. I have a few DBs that are 1GB+ and would like to load them into memory. Because of this, I'm shying away from a Linode HA setup because for the price I could do it with two dedicated like I described. Am I mad or an idiot? What are people out there doing for pseodu high availability good performance setups under $400/month? I'm a webmaster; I do a lot of things none of it that well :)

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• High Availability

  - by mattjgilbert

  Udi Dahan presented at the UK Connected Systems User Group last night. He discussed High Availability and pointed out that people often think this is purely an infrastructure challenge. However, the implications of system crashes, errors and resulting data loss need to be considered and managed by software developers. In addition a system should remain both highly reliable (backwardly compatible) and available during deployments and upgrades. The argument is that you cannot be considered highly available if your system is always down every time you upgrade. For our recent BizTalk 2009 upgrade we made use of our Business Continuity servers (note the name, rather than calling them Disaster Recovery servers ? ) to ensure our clients could continue to operate while we upgraded the Production BizTalk servers. Then we failed back to the newly built 2009 environment and rebuilt the BC servers. Of course, in the event of an actual disaster there was a window where either one or the other set were not available to take over – however, our Staging machines were already primed to switch to production settings, having been used for testing the upgrade in the first place.   While not perfect (the failover between environments was not automatic and without some minimal outage) planning the upgrade in this way meant BizTalk was online during the rebuild and upgrade project, we didn’t have to rush things to get back on-line and planning meant we were ready to be as available as we could be in the event of an actual disaster.

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• The latest version of the EJB 3.2 spec available on java.net project

  - by Marina Vatkina

  If you are not following us on the users alias, here is a quick update. Just before JavaOne, I uploaded the latest version of the EJB 3.2 Core document to the ejb-spec.java.net downloads. If you want to see the detailed changes, download it If you are interested in the high-level list, or would like to know what to look for, this is the list of changes since the previous version (found on the same download page): Specified that the SessionContext object in a the singleton session bean is thread-safe Clarified that the EJB timers distribution and failover rules apply only to persistent timers Clarified that non-persistent timers returned by getTimers and getAllTimers methods are from the same JVM as the caller Fixed section numbering (left over after moving it to its own chapter) in Ch 17 Noted that only 3.0 and 3.1 deployment descriptors are required to be supported in EJB 3.2 Lite for prior versions of the applications Fixes for EJB_SPEC-61 (Ambiguity in EJB lite local view support) and EJB_SPEC-59 (Improve references to the component-defining annotations) JMS/MDB changes: added new standard activation properties and the unique identifier, and rearranged sections for easier navigation Fixed unresolved cross-refs Updated the rule: only local asynchronous session bean invocations are supported in EJB 3.2 Lite Synchronized permissions in the Table with the permissions listed for the EJB Components in the Java EE Platform Specification Table EE.6-2 Specified that during processing of the close() method, the embeddable container cancels all pending asynchronous invocations and non-persistent timers Updated most of the referenced documents to their latest versions Happy reading!

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• Can Ping but Cannot Telnet directly to SQL Server 2012 Cluster Nodes

  - by tresstylez

  We have a monitoring tool (Solarwinds Orion) that needs to connect to a 2-node failover SQL Server Cluster. For reasons outside of our control -- we cannot monitor the CLUSTER IP directly at this time, so we have fallen back to monitoring each cluster node IP directly. This is not working. Upon troubleshooting, we tried to test that the cluster node was listening on the proper (fixed) port by using telnet to the cluster node IP/port -- and the telnet failed. However, telnet'ing to the Cluster IP/Port was SUCCESSFUL! Each node has its own IP. Each node is listening on the identical FIXED port. Each node has Dynamic Ports disabled. Each node can be PINGED successfully from the monitoring tool. Windows Firewall is DISABLED. How can I troubleshoot why I cannot telnet to the listening port on the cluster nodes?

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• So what is Active GridLink for RAC?

  - by Ruma Sanyal

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 I had referred to Active GridLink for RAC in my blog yesterday and since then got several questions on this topic. So I decided to re-visit Active GridLink. With the release of version 11g, Oracle WebLogic Server started to provide strong support for the Real Application Clusters (RAC) features in Oracle Database 11g, minimizing database access time while allowing transparent access to rich pooling management functions that maximizes both connection performance and availability. WebLogic is the only application server in the marketplace which has been fully integrated and certified with Oracle Database RAC 11g without losing any rich functionality. Active GridLink provides Fast Connection Failover (FCF), Runtime Connection Load-Balancing (RCLB), and RAC instance graceful shutdown. With the key foundation for providing deeper integration with Oracle RAC, this single data source implementation in Oracle WebLogic Server supports the full and unrestricted use of database services as the connection target for a data source. For more details and to understand how our customer NEC leverages this capability, read the whitepapers on this topic. Get in depth ‘how-to’ details from this youtube video from our resident expert, Frances Zhao.

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• reaching 99.9999% uptime

  - by christopher-mccann

  I am currently developing a project which is mission-critical. The actual domain name is registered with 1 & 1 and I plan on purchasing DynDNS Custom DNS service (which has 5 different geographical locations for DNS) and then another secondary DNS service to make sure my DNS is as failover safe as possible. Does it matter that the registration is with 1 & 1 - are they a weak link in the chain? All I really use them for is to say that DynDNS is my primary DNS nameserver and then my secondary DNS is my other nameserver. I can transfer the registration to DynDNS - Im just not sure if it really matters or not. Thanks

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• Impact of Server Failure on Coherence Request Processing

  - by jpurdy

  Requests against a given cache server may be temporarily blocked for several seconds following the failure of other cluster members. This may cause issues for applications that can not tolerate multi-second response times even during failover processing (ignoring for the moment that in practice there are a variety of issues that make such absolute guarantees challenging even when there are no server failures). In general, Coherence is designed around the principle that failures in one member should not affect the rest of the cluster if at all possible. However, it's obvious that if that failed member was managing a piece of state that another member depends on, the second member will need to wait until a new member assumes responsibility for managing that state. This transfer of responsibility is (as of Coherence 3.7) performed by the primary service thread for each cache service. The finest possible granularity for transferring responsibility is a single partition. So the question becomes how to minimize the time spent processing each partition. Here are some optimizations that may reduce this period: Reduce the size of each partition (by increasing the partition count) Increase the number of JVMs across the cluster (increasing the total number of primary service threads) Increase the number of CPUs across the cluster (making sure that each JVM has a CPU core when needed) Re-evaluate the set of configured indexes (as these will need to be rebuilt when a partition moves) Make sure that the backing map is as fast as possible (in most cases this means running on-heap) Make sure that the cluster is running on hardware with fast CPU cores (since the partition processing is single-threaded) As always, proper testing is required to make sure that configuration changes have the desired effect (and also to quantify that effect).

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• Hyper V cluster - one VM won't migrate

  - by Chris W

  We have a Failover Cluster built up on 6 blades, each running Hyper V. Each box is running Server 2008 R2. We've got a number of VMs running that all have the same basic config: VHD stored on a cluster shared volume. 2 virtual NICs (1 for LAN connection and 1 for SAN connection). All of our VMs will happily migrate between any other blade apart from one single VM which is running fine on it's current blade but will not migrate to any other location. What could be the cause of it or where should I look to get a detailed error message as I can't seem to find much information logged in any of the logs. Edit: I know the usual culprit is mis-matching resource names. We've already been there with the NICs named differently on some of the blades. As far as we can tell now everything looks to be identical on each bit of metal.

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• DRBD with MySQL

  - by tdimmig

  Question about using DRBD to provide HA for MySQL. I need to be sure that my backup MySQL instance is always going to be in a functional state when the failover occurs. What happens, for example, if the primary dies part way through committing a transaction? Are we going to end up with data copied to the secondary that mysql can't handle? Or, what if the network goes away while the two are syncing, and not all of the data makes it across. It seems like it's possible to get into a state where incomplete data on the secondary makes it impossible for mysql to start up and read the database. Am I missing something?

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• Can't browse computer via nlb cluster name

  - by peg_leg

  I have a fileserver nlb cluster, currently set to single affinity, made up of 2 2008R2 servers. We switched the primary node today. Now our Windows XP workstations can't browse to the cluster name (i.e. \fileserver) but can browse to the cluster ip address (i.e. \192.168.1.1) and can browse the member server by name (i.e. \filesvr1). I remember having a similar issue when we had to change a registry setting to allow Windows XP boxes to see another file server that was in a failover cluster but had to be referred to by another name (\thisfileserver instead of \fileserver). Convoluted, for sure, but it helped to prevent any code changes from happening. Well all of the programmers have their code on \fileserver and we can't have them switch their links every time \filesvr1 supercedes \filesvr2 or vice versa. I can't remember that registry setting that allowed the file server to ignore that it's being called by the wrong name. HELP!

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• So You Want To Build a SPARC Cloud

  - by user12601629

  Did you ever wish you could get the industrial strength power of UNIX/RISC with the flexibility of cloud computing?  Well, now you can!  With recent advances from Oracle it's possible to build an incredibly high-performance, flexible, available virtualized infrastructure based on Solaris and SPARC.  Here's the recipe! Authored in collaboration across the Oracle "Systems Group" team, we now have a complete best practice guide for you.  Click below to download it: Best Practices for Building a Virtualized SPARC Computing Environment Inside you'll find recommendations for how and when to leverage technologies like: SPARC T4 OVM for SPARC hypervisor (version 2.2 and newer) Solaris 11 Ops Center 12c ZFS Storage Appliance Oracle network switches Based on following these best practices, you'll be able to construct a dynamic, virtualized infrastructure that allows for: Easy, GUI-based provisioning on new VMs Automated HA failover in the event of physical server failures Automatic load balancing across a cluster of VM hosts Complete end-to-end monitoring You should download this paper and check it out.  Even if you aren't planning on buying all new hardware, and instead want to transform some existing gear into a dynamic virtualized environment then this paper will give you concrete info on what to do and the trade-offs you'll make. Have fun getting started on your journey to build a SPARC cloud!

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• Can I use Veritias Storage Manager to provide HA storage using server-local storage?

  - by Paul

  I have a need to provide an high-availability ftp/http file repository. Upload will happne to one server, but the uploaded file must be immediately visisble on all other servers I can handle the failover of the servers themeselves using load balancers. But in the event of failure of one server, the other servers must see the same contents of the repository. Normally, I'd use a SAN for this, but in this case the data centre standards do not allow SAN/external storage - all storage will be local to the servers. Cam I use Veritas Storage Manager (or any other product) to manage mirroring hte contents between servers in this way? Or does that require a SAN? I couldn't tell either way from a quick look at the data sheets etc.

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• RSAT and double accounts

  - by Ryaner

  Since we are looking at migrating our domain admins to use non domain-admin accounts and runas for admin tasks a discussion has begun. How do others use RSAT with runas? I know you can Shift+RightClick run as other user to launch it with admin rights, but it looses the icon on the taskbar. The question also has been put, why do Microsoft release the RSAT tools if they recommend admins to run using non-domain accounts. Edit: Further to this, some of the initial testing with RSAT via the run as other user command hasn't worked out well. Few of the options don't function in the Hyper-V and Failover Cluster Manager.

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• mongodb replication: no primary elected

  - by Max

  I have three servers with mongod installed on it running as a replication set. Suddenly the two secondories became unavailable (the mongod process died) - I think because they were too stale. The problem is that the original PRIMARY is now the SECONDARY and my application doesn't work because it can't connect to a PRIMARY. I mean, in which way does that help me? If the replica set can't do failover?! Am I missing something? Furhtermore I am asking myself why did the SECONDARIES die / why are they too stale? What can I do about it? FYI: My database is quite big (40GB on disk).

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• Moving to Data Center

  - by Won

  Please, give me any advice. Our company has decided to move servers to a data center since we are having a major network traffic jam. The data center provides 100MB bandwidth and full 42 unit cabinet for us. Right now, I am planing to have two firewalls for a failover and changing DNS informations for a web server. Is there anything that I have aware of before I move them to the data center? 1. Web Server 2. Exchange Server 3. SQL Servers

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• Server Sizing Methodology

  - by adbrpc

  Our development environment consist of JBoss 5.0.1 DB Server, SQL Server 2008, Oracle IDM. Hardware is Win 2008 32 bit, 4GB RAM. We have reached stage where our environment can not handle application resulting in JBoss shut down throwing out of memory errors and CPU reaching to 90% usage. I am looking methodology to calculate correct server sizing where I input TPS, max number of concurrent users, max CPU utilization etc.. to give me number of servers, RAM size, number of cores. I am expecting application to grow 10% annually. Load Balancer and Failover should also be taken in account while sizing.

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• Route using certain IP address

  - by spa

  I have a server with two public IPs. Both IPs are added to eth0 using ip addr add. Now I'd like to contact a server which uses IP address filtering. Only requests are allowed which use the second IP address. Is there are way to set this up using the standard route command in Linux? I guess that's not the case. So the only solution I see right now: Setup a virtual device let's say eth0:0 and bind the second IP address to it. Then I can reference the device in the route command. Edit: I can't use the second IP as primary one easily as this IP is used as failover IP.

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• SQL 2008 R2 Mirroring Issue

  - by CWL

  Windows 2008 R2 with SQL 2008 R2 - Using Mirroring of a Database across the WAN in a HA setup with one witness. One issue I am having is during a failure (ever so often) the system fails over or tries, but leaves both databases in a Restoring State. My guess is the failover issue happens when there is a WAN bouncing and the systems get confused. The usual fix is to reboot the sql servers. Has anyone seen this type of failure? While this does not happen often it does causes an issue and concern with HA not being trusted fully.

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• In terms of load handling, which is better: one server or two of equivalent power?

  - by seldary

  My goal is to figure out if i'm better off with one strong server, or multiple weaker servers with a load balancer. Does the fact of splitting the load between servers have an effect on the total load my website could take? It's hard to single that out, because there are of course a lot of parameters that affect the results, so some assumptions: Putting failover considerations aside - I know it matters, but for the sake of the question's simplicity, lets assume nothing fails. The servers in the multiple servers option have an accumulated "power" equivalent to the one server option (about the same amount of cores and RAM space). If that is too theoretical, here is a concrete question that could help: Suppose I have several instances of exactly the same server - lets call it S. Suppose that server S can serve a load of up to X calls per time unit. Will two S servers with a load balancer serve 2X calls per time unit? significantly more? significantly less?

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