![\"Azure](\"https:\/\/devblogs.microsoft.com\/cosmosdb\/wp-content\/uploads\/sites\/52\/2024\/01\/azure-samples-cosmsos-db-design-patterns.jpeg\")
<\/p>\nOver the years, customers have asked us for help in designing applications around specific scenarios they were trying to achieve. In some cases, these centered around implementing certain patterns using a JSON-based NoSQL database. Some of these patterns are very common in the NoSQL world, but not well understood by those new to NoSQL databases. Other patterns were very specific to the Cosmos DB service itself in demonstrating how to leverage specific capabilities to solve difficult architectural challenges.<\/p>\n
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We\u2019ve been capturing these patterns and sharing them with customers individually. We felt now was a good time to publish some of these more broadly to make more discoverable by users. The result is Azure Cosmos DB Design Patterns<\/a>. A repository on GitHub that includes a wide variety of samples that show how to implement specific patterns that will allow you to solve design-related challenges when using Azure Cosmos DB for your solutions.<\/p>\n To help share these, we\u2019ve created a blog post series on each of them. Each post will focus on a specific design pattern with a corresponding sample application that\u2019s featured in this repository. We hope you enjoy and find this series useful.<\/p>\n Here\u2019s a list of the previous posts in this series:<\/p>\n This blog post will focus on the Global Distributed Lock Pattern example we\u2019ve provided in this GitHub repository<\/a>. The NoSQL Global Distributed Lock Design Pattern is designed for synchronizing access to shared resources in distributed systems. It allows a process to acquire a global lock, ensuring exclusive access to a resource and preventing concurrent modifications. This pattern is superior to regular locks as it handles challenges like network delays, system failures, and data partitioning in a distributed environment. Key features include fence tokens for secure operation ordering, high availability, fault tolerance, scalability, and effective management of network partitions and failures. It’s ideal for large-scale applications requiring consistent access to shared resources across multiple nodes.<\/p>\n A distributed global lock in the NoSQL design pattern is commonly used for enforcing mutual exclusion or coordination across multiple nodes or processes in a distributed system. Here are some examples:<\/p>\n Utilizing a distributed global lock allows for the coordination and synchronization of actions across multiple nodes or processes, thus ensuring consistency and preventing conflicts in a distributed setting. However, it\u2019s vital to recognize the complexity in correctly and efficiently implementing distributed locks. The specific mechanisms and techniques employed may vary depending on the NoSQL database in use.<\/p>\n In this example, the application generates a Lock using a user-provided Name and Time to Live (TTL). This Lock is established within Azure Cosmos DB, allowing it to be monitored by multiple worker threads distributed across various locations. The example illustrates this by creating three threads that persistently attempt to acquire the lock. Once a worker thread successfully obtains the lock, it retains it for a randomly determined duration in milliseconds before relinquishing it. Should the lock not be released within the specified TTL, it is automatically freed.<\/p>\n The implementation leverages the TTL feature to automatically dispose of a lease object, eliminating the need for clients to manually verify a ‘leasedUntil<\/span>‘ date. However, there’s still a requirement to ensure that two clients aren’t attempting to lease the same object simultaneously. This concurrency check is efficiently handled in Azure Cosmos DB using the ‘etag’ property associated with the object. The screenshot provided demonstrates the Distributed Lock Application in operation.<\/p>\n The use of the Global Distributed Lock Design Pattern is crucial for software developers, particularly when dealing with distributed systems, for several key reasons:<\/p>\n In summary, the Global Distributed Lock Design Pattern is a vital tool for software developers working with distributed systems, as it addresses key challenges such as data consistency, race conditions, synchronization, scalability, and system reliability.<\/p>\n You can review the sample code by visiting the\u00a0Global Distributed Lock Pattern\u00a0on GitHub<\/a>. You can also try this out for yourself by visiting the\u00a0Azure Cosmos DB Design Patterns<\/a>\u00a0GitHub repo and cloning or forking it. Then run locally or from Code Spaces in GitHub. If you are new to Azure Cosmos DB, we have got you covered with a\u00a0free Azure Cosmos DB account\u00a0<\/a>for 30 days, no credit card required. If you want more time, you can extend the free period. You can even upgrade too.<\/p>\n Sign up for your free Azure Cosmos DB account at\u00a0aka.ms\/trycosmosdb<\/a>.<\/p>\n Explore this and the other design patterns and see how Azure Cosmos DB can enhance your application development and data modeling efforts. Whether you\u2019re an experienced developer or just getting started, the free trial allows you to discover the benefits firsthand.<\/p>\n To get started with Azure Cosmos DB Design Patterns, follow these steps:<\/p>\n Azure Cosmos DB is a fully managed and serverless distributed database for modern app development, with SLA-backed speed and availability, automatic and instant scalability, and support for open-source PostgreSQL, MongoDB, and Apache Cassandra.\u00a0Try Azure Cosmos DB for free here.<\/a>\u00a0To stay in the loop on Azure Cosmos DB updates, follow us on\u00a0Twitter<\/a>,\u00a0YouTube<\/a>, and\u00a0LinkedIn<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":" Over the years, customers have asked us for help in designing applications around specific scenarios they were trying to achieve. In some cases, these centered around implementing certain patterns using a JSON-based NoSQL database. Some of these patterns are very common in the NoSQL world, but not well understood by those new to NoSQL databases. […]<\/p>\n","protected":false},"author":39313,"featured_media":7442,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[14],"tags":[1882],"class_list":["post-7441","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-core-sql-api","tag-design-patterns"],"acf":[],"blog_post_summary":" Over the years, customers have asked us for help in designing applications around specific scenarios they were trying to achieve. In some cases, these centered around implementing certain patterns using a JSON-based NoSQL database. Some of these patterns are very common in the NoSQL world, but not well understood by those new to NoSQL databases. 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Azure Cosmos DB design pattern: Global Distributed Lock<\/h2>\n
![\"Azure](\"https:\/\/devblogs.microsoft.com\/cosmosdb\/wp-content\/uploads\/sites\/52\/2024\/01\/dist-lock.jpg\")
<\/a><\/p>\nThe Scenario:<\/h2>\n
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Sample Implementation:<\/h2>\n
![\"A](\"https:\/\/devblogs.microsoft.com\/cosmosdb\/wp-content\/uploads\/sites\/52\/2024\/01\/a-screenshot-of-a-computer-program-description-au.png\")
<\/p>\nWhy It Matters:<\/h2>\n
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Getting Started with Azure Cosmos DB Design Patterns<\/h2>\n
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About Azure Cosmos DB<\/h3>\n