We have already understood the mechanism of dumping a fork sub-process to generate an hprof file. I believe everyone is also aware that since a sub-process can be created in the native layer to perform the dump hprof operation, it is natural that the hprof file can also be parsed in the sub-process at the […]
Tag: snapshot
New ECMAScript proposals: AsyncContext.Variable and AsyncContext.Snapshot
Hello everyone, my name is Ruochuan. I have been organizing source code reading activities for nearly a year. If you are interested, you can click here to scan the code and add me on WeChat lxchuan12 to participate. Every week everyone will learn about 200 lines of source code together and make progress together. At […]
Why doesn’t Redis’ “snapshot” block other requests?
Although we often regard Redis as a pure memory key-value storage system, we also use its persistence function. RDB and AOF are the two persistence tools provided by Redis, among which RDB is the data snapshot of Redis. , in this article we want to analyze why Redis needs to use sub-processes when persisting snapshots […]
ADG Snapshot Standby at a point in the past
Introduction When converting physical standby to snapshot standby, this readable and writable copy is the current time. If the required read-write copy is the previous time, the dgmgrl command does not have this option, but it can be done manually. This article describes this manual process. In fact, the process is very simple, but it […]
[Java executable commands] (21) Thread snapshot generation tool jstack: Help developers analyze and troubleshoot thread-related problems (deadlock, infinite loop, thread blocking…)
jstack of Java executable commands 1 concept 2 Advantages and disadvantages 3 use 3.1 Syntax format 3.2 Use steps and skills 3.3 Use cases 4 Application scenarios Summarize 1 concept The jstack command is a diagnostic tool provided in the Java Development Kit (JDK) to generate thread snapshots of the Java Virtual Machine (JVM). Its […]
[Java executable commands] (20) Heap dump snapshot file and heap information viewing tool jmap: generate multi-format heap dump files, print class loader information and view shared object mapping information ~
jmap of Java executable commands 1 concept 2 Advantages and disadvantages 3 use 3.1 Syntax format 3.2 Generating a heap dump file 3.3 Execute the jmap command to check the memory usage 3.4 Execute the jmap command to print object statistics 4 Application scenarios Summarize 1 concept jmap is a tool that comes with Java […]
React 18 state as a snapshot
reference article state is like a snapshot Maybe state variables look similar to normal readable and writable JavaScript variables. But state is more like a snapshot in its exhibited properties. Setting it will not change existing state variables, but will trigger a re-render. Setting state will trigger rendering It might be thought that the user […]
k8s deploys a new version of elasticsearch+kibana and configures snapshot backup
Version: es 7.17.6 kibana 7.17.6 k8s: 1.19.16 1. Introduction Elasticsearch and Kibana are a pair of powerful open source tools that are often used together to build real-time data analysis and visualization solutions. Elasticsearch: Elasticsearch is a distributed, high-performance real-time search and analysis engine. It is built on top of the open source search engine […]
Android adb shell View App memory (java heap memory/vss virtual memory/detailed memory status/memory snapshot hprof) and system available memory
1.adb shell gets the pid of the app process adb shell “ps|grep com.xxx package name” According to a channel package, to query the corresponding pid, as follows: 2. View the maximum value of java dalvik heap memory of the device through adb shell Execute the command line: adb shell getprop dalvik.vm.heapgrowthlimit If the java heap […]
KVM disk snapshot clone
KVM disk snapshot clone KVM virtual machine disk format conversion Just now we found that the virtual machine file created by KVM The following format This raw is our virtual machine file [root@kvm01 data]# ls centos2.raw CentOS-7-x86_64-DVD-1804.iso [External link picture transfer failed, the source site may have an anti-theft link mechanism, it is recommended to […]