Tech Tips, Tricks & Trivia

I recently took a quiz using the Chrome browser. After submitting my answers, I was curious to read the explanations for the answers that I got wrong on the subsequent results page. As I had to multi-task, I had to switch to another activity & when I got back to the tab with the results, annoyingly Chrome automatically refreshed the page and content was gone! I discovered that this is actually caused by an experimental feature called Tab Discarding in Chrome that seeks to conserve its memory footprint. Unfortunately, the user has to pay the price for Chrome's self-maintenance job which is enabled by default. If you find this feature annoying rather than helpful, here's how you can disable it - * Go to chrome://flags/#automatic-tab-discarding in Google Chrome. * In the section titled “Automatic tab discarding,” change Default to Disabled. * Click “Relaunch Now” to relaunch Chrome and apply the change. Chrome will no longer discard your unused tabs. Disabling th...

This Week I Learned - * SQL Server Managed Backup to Microsoft Azure is recommended for SQL Server running on Windows Azure Virtual Machines. It stores the metadata in the msdb database and uses system jobs to write full database and transaction log backups. SQL Server Managed Backup to Microsoft Azure can be configured at the database level or at configured with default settings for an instance of SQL Server. *  The Indian Rail Catering and Tourism Corporation (IRCTC), designed an Internet-based ticketing system. Initially, tickets were delivered by courier to customers and in they moved to a completely web-based e-ticketing system where tickets could be printed using a web-based application.  Centre for Railway Information Systems (CRIS) uses Pivotal GemFire, a distributed in-memory database which is part of Pivotal Big Data Suite, to support high concurrent transactions for reservations and ticket purchases in the newly launched Indian Railways next generation e-ticket...

The following table from the SAP on Azure Solutions home page summarizes what's supported & certified - SAP Product Licensing Database Operating System SAP-certified VMs Storage Support SAP NetWeaver Bring your own license SQL Server, Oracle (Windows and Oracle Linux only), DB2, SAP ASE Windows SUSE Linux Enterprise Red Hat Enterprise Linux A5 to A11 D11 to D14 DS11 to DS14 DS11_v2 to DS15_v2 GS1 to GS5 M-series Premium storage 32 GB–4 TB (recommended for DB and I/O intensive workloads) Standard storage 32 GB–4 TB Managed Disks are recommended Pro Direct Premier Business All-in-One Business Suite Software Windows SUSE Linux Enterprise Red Hat Enterprise Linux Oracle Linux BusinessObjects BI N/A Windows SAP HANA, SAP Business Suite on HANA, SAP S/4HANA (OLTP workloads) SAP HANA SUSE Linux Enterprise Red Hat Enterprise Linux M64s, M64ms, M128s, M128ms SAP BW on HANA, SAP BW/4HANA (OLAP workloads) M64s,...

Short notes from various online resources, including: Introduction to Docker Docker Container Overview for Business Leaders Key Docker terms: Image - The basis of a Docker container. The content at rest. Think of image as a powered down container A container image is an immutable package that contains all the application code, system packages, binaries, libraries, configuration files, and the operating system running in the container. Container   - The image when it is ‘running’ or  the in-memory instance of an image.  It is the standardized packaging for software and dependencies.  A container is essentially a runtime that contains the bare essentials needed to run a unique application. The kernel or core part of the host operating system and services such as storage are shared across a host. The shared kernel enables containers to be light weight. A container image is immutable. Once you've built an image, the image can't be changed. The only ...

This Week I Learned - * Site Recovery replicates data from on-premises to Azure storage over a public endpoint, or using ExpressRoute public peering. Replication over a site-to-site VPN network isn't supported . When you replicate to Azure, replication traffic reaches the public endpoints of an Azure Storage account, Thus you can only replicate over the public internet with ExpressRoute ( public peering  or Microsoft peering ), and VPN doesn't work.  After the virtual machines have been failed over to an Azure virtual network you can access them using the private peering setup with the Azure virtual network. Replication is not supported over private peering .  You can create a site-to-site VPN, with an Azure virtual network. This doesn't interfere with Site Recovery replication. *  Azure Backup supports VMware and Hyper-V virtual machines running on Linux and Windows, as well as physical Windows  Servers . *  Currently, more Azure VM types are ce...

Some facts about the recipients of Bharat Ratna , India's highest civilian award - Bidhan Chandra Roy, M. Visvesvaraya, A. P. J. Abdul Kalam, C. V. Raman, C. N. R. Rao are the men of  science who have been bestowed with the award M. S. Subbulakshmi, Ravi Shankar, Lata Mangeshkar and Bismillah Khan, Bhimsen Joshi  are awardees from the world of music Nelson Mandela, Khan Abdul Ghaffar Khan/Bacha Khan/'Frontier Gandhi', Mother Teresa are foreign born Indian Theosophist & Sanskrit scholar, Bhagwan Das who was awarded Bharat Ratna in 1955,   was an opponent of rioting as a form of protest. Sachin Ramesh Tendulkar is the youngest recipient to date (at 40) and the first ever sportsperson to receive the award. Maharishi Karve/Dhondo Keshav Karve was awarded the Bharat Ratna, in 1958, the year of his 100th birthday

A relative recently asked me about the biographies and autobiographies I've read when the topic about favorite books came up. Here are some that I've read & enjoyed (marked in bold) - Al Jaffee's Mad Life: A Biography Tunnel of Time by RK Laxman C V Raman : A Biography  - Uma Parameswaran  I Too had a Dream - Verghese Kurien How to Fail at Almost Everything and Still Win Big: Kind of the Story of My Life - Scott Adams , part biography, part advise My Life and Medicine - Dr S Padmavati    Satyajit Ray - The Inner Eye The Rebel: A biography of Ram Jethmalani Fall of the Sparrow - Salim Ali A Shot At History: My Obsessive Journey To Olympic Gold - Abhinav Bindra The Autobiography of  Benjamin Franklin The Story Of My Experiments With Truth - Mahatma Gandhi My Days  - RK Narayan Kishore Kumar: Method in Madness The Last Lecture  - Randy Pausch Beyond the Last Blue Mountain - JRD Tata Inventive Wizard: George Westinghouse Hit Refresh...

This Week I Learned - *  Per Azure subscription the default quota for virtual machine CPU cores is 20 * The current pricing of Managed Disks shows that the newly introduced Standard SSD disks are cheaper than Standard HDD disks. * Many database workloads are not CPU-intensive. Azure offers certain VM sizes where you can constrain the VM vCPU  count to reduce the cost of software licensing , while maintaining the same memory, storage, and I/O bandwidth. The new Azure VM sizes (in D, G & M series) allow workloads to push higher CPU utilization at a fraction of the (per-core) licensing cost. *  There are two types of subnets in a VNet, a gateway subnet and a virtual machine-hosting subnet . * P2S uses the Secure Socket Tunneling Protocol (SSTP). S2S and VNet-to-VNet VPN connections use IPsec tunnel mode with AES256. ExpressRoute is a private WAN connection * The name of a virtual network must be unique within a resource group, but can be duplicated within a su...

You can communicate with most Azure resources over the Internet through public IP addresses. When you deploy Azure services in a virtual network, you can communicate with the service resources privately, through private IP addresses. Below is a list of services that can be deployed into a virtual network : Virtual machines: Linux or Windows Service fabric Virtual machine scale sets HDInsight App Service Environment RedisCache API Management VPN Gateway Application Gateway (internal) Azure Kubernetes Service (AKS) Azure Container Service Engine with the Azure Virtual Network CNI plug-in Azure Active Directory Domain Services: Virtual network (classic) only Azure Batch Cloud services: Virtual network (classic) only Azure SQL Database Managed Instance Last updated: 22-Sep-2018

Notes from the official documentation - Options Automated Backup Azure Backup for SQL Manual backup Description * Allows you to schedule regular backups for all databases on a SQL Server VM. * Backups are stored in Azure storage for up to 30 days. * Beginning with SQL Server 2016, Automated Backup v2 offers additional options such as configuring manual scheduling and the frequency of full and log backups. * Enabled by the SQL Server IaaS Agent Extension, which is automatically installed on SQL Server Windows virtual machine images in the Azure portal. * Can centrally manage backups for multiple servers and thousands of databases. * All backups are stored and managed in a Recovery Services vault. * Policy driven backup and retention * Support for SQL Always On * Databases can be restored to a specific point in time in the portal. * It offers a customizable retention policy that can maintain backups for years. * This feature is currently in pub...

Info from the official documentation - Oracle supports running Oracle DB 12.1 Standard and Enterprise editions in Azure on virtual machine images based on Oracle Linux . High availability and disaster recovery for Oracle Database Enterprise Edition (without relying on Oracle RAC) can be achieved on Azure using Data Guard , Active Data Guard, or Oracle Golden Gate , with two databases on two separate virtual machines. Both virtual machines should be in the same virtual network to ensure they can access each other over the private persistent IP address. According to Oracle Support note Doc ID 2178595.1 , JD Edwards EnterpriseOne versions 9.2 and above are supported on any public cloud offering that meets their specific Minimum Technical Requirements (MTR). You need to create custom images that meet their MTR specifications for OS and software application compatibility. While Microsoft recommends using the latest public, supported version of Java (currently Java 8), Azure also ...

This Week I Learned - *  The Azure Dv3 & Ev3 family of VMs use Hyper-Threading . This is something to note for those concerned  with  Oracle cloud-licensing. *  After a VM  is created, you can add or remove a NIC (unless it's the last NIC on the VM) *  Managed disks provide better reliability for Availability Sets by ensuring that the disks of VMs in an Availability Set are sufficiently isolated from each other to avoid single points of failure *  Microsoft recommends using a separate storage account for each VM in an Availability Set. *  Azure uses Live Migration technology to migrate the Virtual Machines from the failing hardware to a healthy physical machine. Live Migration is a VM preserving operation that only pauses the Virtual Machine for a short time. Memory, open files, and network connections are maintained, but performance might be reduced before and/or after the event. In cases where Live Migration cannot be used, the VM...

With the loads of user data that LinkedIn keeps, it has compiled a list of 25 companies where it thinks India wants to work now based on the actions of users - Directi  Flipkart  One97/Paytm Amazon  AB InBev McKinsey Google/Alphabet KPMG India EY  OYO  Daimler AG/Mercedes-Benz Adobe  Expedia  Morgan Stanley DBS Bank Ola  GE MakeMyTrip PwC India Goldman Sachs Shell  JPMorgan Chase & Co. Unilever  Reliance Industries Deloitte India The analysis that went into the LinkedIn List only includes companies with over 500 employees; takes into account actions from the 12 months ending in January; rolls up a company’s wholly-owned subsidiaries into the parent company’s final score and description The article also lists interesting incentives and perks that these companies offer - McKinsey under its ‘Take Time’ program offers employees five to 10 extra weeks off to pursue their passion – get a pilot’s lice...

The Pluralsight video course Docker and Containers: The Big Picture by Nigel Poulton provided a good introduction but I found it to be needlessly long Key points from the 1hour 47minute course released in 22 Dec 2015 - Container is a standardized unit of software Open Container Initiative is responsible for Container format and runtime standards Docker and containers can handle stateful and stateless workloads Docker storage backend is pluggable Docker containers are peristent Stopping a container doesn't wipe its data. Restarting a container brings its data back Container data stored in volumes persists even after the container is destroyed Container Registries are places to store & retrieve container images Docker Hub is the official Docker Registry Registries contain Repositories Registries are the enterprise IT App Store Repositories can be public or private Public repositories are open for pulling (downloading) but not for pushing (uploading changes) Doc...

Cost of outbound data transfers vary according to Azure Service - while for some it is free, for others it can be significant if the volume is high. All inbound data transfer is free of charge Application Gateway service - Data transferred out of Azure data centers from the application gateways will be charged at standard data transfer rates. Azure Site Recovery - Costs are incurred during test failover, where the virtual machine, storage, egress and storage transactions costs will be applied. Azure Backup  - Customers will not be charged for any restore operations or outbound network bandwidth (egress) that is associated with restore operations. ExpressRoute - All inbound and outbound data transfer is free of charge with Unlimited Data plan. All outbound data transfer is charged based on a pre-determined rate as per zone for Metred Data plan Azure Virtual Network - data going out of Azure data centers between two virtual networks is billed a...