St Louis
-
8 min readWhen a closure captures a variable in Rust, by default it captures it by reference. This means that the closure cannot modify the variable that it captures. However, if you want to modify the captured variable, you can use the mut keyword when defining the closure to indicate that it is mutable.For example, if you have a variable x that you want to modify within a closure, you can define the closure like this: let mut x = 5; let mut modify_x = || { x += 1; }; modify_x(); println.
-
6 min readIn Groovy, you can replace an interface method by using the @DelegatesTo annotation. This annotation allows you to specify a delegate type that should be used to implement the interface methods. To replace an interface method in Groovy, you can create a class that implements the interface and then uses the @DelegatesTo annotation to delegate method calls to a Closure or method in the class.
-
4 min readIn Hadoop, the block size is an important parameter that determines how data is stored and distributed across the cluster. Setting the block size properly can have a significant impact on performance and storage efficiency.To set the Hadoop block size properly, you first need to consider the size of the data you are working with and the requirements of your applications.
-
4 min readTo generate random Unicode strings in Rust, you can use the rand crate to generate random bytes and then convert them to Unicode characters. This can be achieved by first generating random bytes using thread_rng().gen::<[u8; n]>() function from the rand crate, where "n" is the length of the byte array you want to generate. Next, you can convert these bytes to a UTF-8 string using the String::from_utf8_lossy() function.
-
6 min readTo read data content in Jenkins using Groovy, you can use the readFile method which allows you to read the content of a file located within the Jenkins workspace. You can specify the path to the file as a parameter to the readFile method, like this: def fileContent = readFile 'path/to/your/file.txt' This will read the contents of the file located at path/to/your/file.txt and store it in the variable fileContent as a string.
-
5 min readTo setup Hive with Hadoop, you first need to have Hadoop installed and running on your system. Once that is done, you can proceed with setting up Hive.You will need to download the Hive package from the Apache Hive website and extract it to a directory on your system.Next, you will need to configure the hive-site.xml file to specify the necessary configurations for Hive to work with Hadoop.
-
5 min readTo define a pointer to a trait function in Rust, you can use the Fn trait. First, define a trait with the desired function signature. Then, create a variable that holds a reference to a function that implements the trait. You can then call this function through the pointer as needed. Additionally, you can use the fn keyword to define a function pointer directly. This allows you to define the function signature inline and assign it to a variable.
-
7 min readTo fetch Jenkins logs between two timestamps using Groovy, you can use the Jenkins API to access the build log and extract the information within the specified timeframe. You can write a Groovy script that makes a request to the Jenkins API, retrieves the build log, and then filters the log entries based on the provided timestamps. By parsing the log entries and checking the timestamps, you can extract the relevant information that falls within the specified time range.
-
6 min readTo get raw Hadoop metrics, you can use the JMX (Java Management Extensions) technology that allows you to monitor and manage the performance of Java applications. Hadoop provides several metrics related to different components such as NameNode, DataNode, ResourceManager, and NodeManager.You can access these metrics through the JMX beans exposed by each of these components.
-
5 min readTo debug a single file without debugging the entire package in Rust, you can use the --filename flag in the rustc command. This flag allows you to specify the name of the file you want to debug. By doing so, you can focus on finding and fixing issues in a particular file without having to navigate through the entire package. This can be useful when you want to isolate and troubleshoot problems in a specific section of your code without being distracted by other parts of the project.
-
3 min readThe default scheme configuration in Hadoop is located in the core-site.xml file. This file can be found in the conf directory within the Hadoop installation directory. The scheme configuration specifies the default file system scheme to be used by Hadoop, such as hdfs:// for Hadoop Distributed File System. By default, this file contains properties that define the default setting for various Hadoop components, including the file system scheme, replication factor, and block size.