Python Authors: Matt Davis, AppDynamics Blog, Pat Romanski, Donald Meyer, Liz McMillan

Blog Feed Post

Calling all Dispatchers

There are two items of general NetWeaver Identity Managementmaintenance that I get asked about frequently.
  • How do you prevent deadlocks    
  • What is the best way to configure my dispatchersin IDM?
All too often these issues are actually related asinefficient dispatcher setup can cause database deadlocks. In this blog entryI’d like to recommend some possible architecture scenarios that will help outwith this. For the purposes of this discussion, we’ll be talking about aNetWeaver IDM 7.1 installation on Microsoft SQL Server 2008 R2. According to Microsoft:
A deadlock occurs when two or more tasks permanently blockeach other by each task having a lock on a resource which the other tasks aretrying to lock. The following graph presents a high level view of a deadlockstate where:
·        Task T1 has a lock on resource R1 and hasrequested a lock on resource R2.
·        Task T2 has a lock on resource R2 and has requesteda lock on resource R1.
·        Because neither task can continue until aresource is available and neither resource can be released until a taskcontinues, a deadlock state exists.

Attaching multiple dispatchers to the same task would thenseem to create the potential for deadlocks to occur in the database,particularly if they are all trying to access the same rows in the various IDMtables. But wait, we’re supposed to be able to do this to encourage HighAvailability, Load balancing and failover, so what gives?

Well the secret lies in the architecture, of course. If therequests come from separate physical hosts, it is much easier for the both IDMand the database to manage the threads and requests. Let’s look at a couple ofexamples. First here is a basic dispatcher setup assuming one server with acouple of dispatchers on it.

This setup is OK since each dispatcher (D) is connected to adistinct Job (J) or set of jobs. Sometimes there is a need to have aconfiguration like this, which usually something like one dispatcher for provisioningjobs, one for housekeeping(HK) and one that provides some sort of elevatedaccess for Directory Services(DS) access.

Based on this there might be a temptation to set up thedispatcher/job relationship to look something like this to provide additionalfail over and support for some specific jobs. Consider the following examplewhere I outline a scenario with a crossover between multiple dispatcherspointing to jobs in a many to one relationship:
This scenario is exactly what we do not want to have as itis most likely to create a deadlock scenario as having multiple dispatchers accessingthe same jobs that are accessing the same database resources. What we have hereis a potential for deadlocks as the system is trying to manage multipledatabase resources (rows) at the same time.

What tends to compound this situation is the way that thedatabase is being accessed. Using the To Identity Store Pass creates the leastamount of deadlock strain on the system, since this is under the direct controlof the workflow system and its dispatchers, while using techniques such as the uIS_SetValue function, that can becalled from anywhere, at any time, create the greatest possibility as thesystem is managing standard job based access with unforeseen access via uIS_SetValue.
This scenario should be replaced by something like this:

In this case the potential for deadlocks is significantlyreduced since there is separate management of the database connections. It alsoprovides a degree of load-balancing and failover since if the D1 or D3Dispatchers are busy or unable to process an assigned task then the D4or D5 dispatchers respectively can take over. A good resource forthis can be found in the SAP document SAPNetWeaver Identity Management Identity Center Implementation Guide OptimizingDispatcher Performance.

What also needs to be recognized is that it’s not always asmuch “where” the requests come from, but when the requests come. Care should betaken to monitor the frequency and duration of the larger and more intensivetasks and workflows to make sure that the more involved tasks do not run at thesame time (For example the HCM load should probably not happen the same timethat the Directory Service reconciliation is occurring). These should be thefirst candidates for having their down dedicated dispatchers if there is a needto run them on similar schedules and this cannot be avoided.

Given all of this, the thing to remember when consideringdispatcher allocation is to make sure that there are not multiple dispatchersthat are competing for the same set of Identity Store resources at the sametime. As long as this is kept in mind when setting up dispatchers, thepossibility of deadlocks is minimized.
A related question to this is how many dispatchers are neededto assign for provisioning and de-provisioning operations. I have always used25,000 objects per dispatcher as a general rule. Based on this the scenarioshown above would be good for an enterprise where there are a maximum of 50,000users, roles, privileges or groups that are being managed in any given task.

As a final note, it is a good thing to remember that thedispatchers do not need to be installed on Microsoft Windows based systemsonly. Any UNIX/LINUX environment is just fine for setting up IDM Dispatchers.For more information, check out the SAP document: HowTo: Setting Up An Identity Management Dispatcher On A Unix Host Flavor.

Read the original blog entry...

More Stories By Matthew Pollicove

Matt Pollicove is an Identity Management architect, engineer, trainer, project manager, author and blogger with experience in user account provisioning, data synchronization, virtual directory and password management solutions. As a MaXware Technical Consultant and later as a System Engineer, he worked extensively with MaXware (now SAP) software products in large customer environments. In the past Matt has worked with several leading national and international consulting firms and is currently a Sr. Principal Consultant for Commercium Technologies. He is currently the Practice Lead for SAP NetWeaver Identity Management and SailPoint IIQ.

@ThingsExpo Stories
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
It is of utmost importance for the future success of WebRTC to ensure that interoperability is operational between web browsers and any WebRTC-compliant client. To be guaranteed as operational and effective, interoperability must be tested extensively by establishing WebRTC data and media connections between different web browsers running on different devices and operating systems. In his session at WebRTC Summit at @ThingsExpo, Dr. Alex Gouaillard, CEO and Founder of CoSMo Software, presented ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
WebRTC is great technology to build your own communication tools. It will be even more exciting experience it with advanced devices, such as a 360 Camera, 360 microphone, and a depth sensor camera. In his session at @ThingsExpo, Masashi Ganeko, a manager at INFOCOM Corporation, introduced two experimental projects from his team and what they learned from them. "Shotoku Tamago" uses the robot audition software HARK to track speakers in 360 video of a remote party. "Virtual Teleport" uses a multip...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
SYS-CON Events announced today that Evatronix will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Evatronix SA offers comprehensive solutions in the design and implementation of electronic systems, in CAD / CAM deployment, and also is a designer and manufacturer of advanced 3D scanners for professional applications.
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
An increasing number of companies are creating products that combine data with analytical capabilities. Running interactive queries on Big Data requires complex architectures to store and query data effectively, typically involving data streams, an choosing efficient file format/database and multiple independent systems that are tied together through custom-engineered pipelines. In his session at @BigDataExpo at @ThingsExpo, Tomer Levi, a senior software engineer at Intel’s Advanced Analytics gr...
When talking IoT we often focus on the devices, the sensors, the hardware itself. The new smart appliances, the new smart or self-driving cars (which are amalgamations of many ‘things’). When we are looking at the world of IoT, we should take a step back, look at the big picture. What value are these devices providing? IoT is not about the devices, it’s about the data consumed and generated. The devices are tools, mechanisms, conduits. In his session at Internet of Things at Cloud Expo | DXWor...
Everything run by electricity will eventually be connected to the Internet. Get ahead of the Internet of Things revolution. In his session at @ThingsExpo, Akvelon expert and IoT industry leader Sergey Grebnov provided an educational dive into the world of managing your home, workplace and all the devices they contain with the power of machine-based AI and intelligent Bot services for a completely streamlined experience.