is the first time you start a Web process, no cache data, and you can find that the first boot Sonic is less than the WEBSO load time by 53%:The second scenario is the first time you start the Web process, the data when the template is updated, and you can see that Sonic is reduced by 22% compared to WEBSO:The third scenario is non-first-boot Web process, template unchanged data update data, sonic less than WEBSO 60%:The fourth scenario is the first time the Web process is started, the cached d
drums ... The drum is a palm, isn't it, elder brother? They are the most ... The best squares!But it ' s too late. The window smashes! A blood-curdling wail rings out into the night. Tom is never seen again. But probably only because he's trying to get out of the writing the next Block of the Week.but it's too late. The window is broken and cracked! The hairy bone frightened the screams of people all night long. No one will ever see Tom again. But probably just because he wanted to write down t
definition resources from the system files. Different application context implementations correspond to different ways of putting in read beandefinition. The rewritten Getresourcebypath can illustrate this point.The details of how the refresh and Getresourcebypath methods are invoked, as well as how the XML file is handled in the example above, will be explained in detail in the next section of the IOC container initialization.Then such containers are easy to use:ApplicationContext context = ne
Before we introduce how servlets work, let's first look at the servlet containers that are matched to the servlet, for example, in TomcatBasic knowledge of 1.Tomcat containersThe container for Tomcat is classified into four levels from the top below: Container,engine,host,context.The container that manages the servlet directly is the context container. A context container in Tomcat corresponds to a web App app2.servlet container Start-up processWhen you add an app to Tomcat, Tomcat creates a ser
router logs the time it receives the packet.⑵record address and timestamps: similar to the previous command, but also stores the IP address of the receiving interface.⑶record timestamps only at the prespecified SYSTEMS: Each router will record the receive time when it receives the packet, but only for some specific IP addresses selected by the carrier.Router Alert optionmarking the packet as requiring special handling, he attempts to establish better QoS for packet traffic. Some important funct
in the kernel as a module.Late_initcall (balanced_irq_init); #define Late_initcall (FN) module_init (FN) //include\linux\init.hIn the balanced_irq_init() function, a kernel thread is created to interrupt load balancing:static int __init balanced_irq_init (void) { ... printk (kern_info "Starting balanced_irq\n"); if (Kernel_thread ( BALANCED_IRQ, NULL, Clone_kernel) >= 0) return 0;else printk (kern_err "balanced_irq_init:failed to spawn Balanced_irq" ); ......}In the balanced_irq() functio
; SPIN_LOCK_BH (ptype_lock); if (Pt->type = = htons (eth_p_all)) //type for Eth_p_all, hang on Ptype_all above List_add_rcu (pt->list, Ptype_all); else { //Otherwise, hang on ptype_base[type15] above hash = Ntohs (pt->type) Ptype_hash_mask; List_add_rcu (pt->list, ptype_base[hash]); } SPIN_UNLOCK_BH (ptype_lock); } Export_symbol (Dev_add_pack); Next we take IPv4 as an example of how reliable and specific protocol stack functions are o
option is configured when the kernel is compiled CONFIG_IRQBALANCE , interrupt load balancing in the SMP architecture will be present in the kernel as a module.Late_initcall (balanced_irq_init); #define Late_initcall (FN) module_init (FN) //include\linux\init.hIn the balanced_irq_init() function, a kernel thread is created to interrupt load balancing:static int __init balanced_irq_init (void) { ... printk (kern_info "Starting balanced_irq\n"); if (Kernel_thread ( BALANCED_IRQ, NULL, Clone_ke
= Drv_name "... "; static struct Vortex_chip_info {...} Vortex_info_tbl[] _ _devinitdata = {{"3c590 vortex 10Mbps",... ... ...} static int _ _init vortex_init (void) {...} static void _ _exit Vortex_cleanup (void) {...} Module_init (Vortex_init); Module_exit (Vortex_cleanup);Macro-label-based optimizations:Linux uses a number of macros to set special properties on some functions and data structures. These grand many are defined inInclude/linux/init.h. Some macros tell the linker to place code o
, not their wrapping functions. and lock and unlock yourself to get more time to hold the lock. The real device cannot be removed from the user's command and will be removed at the time of uninstallation. Virtual devices can be de-removed through user commands, but whether delisting succeeds depends on the virtual device-driven design. Virtual Appliance This article does not introduce much, and then add a separate blog post for the difference between the virtual device and the real device .Locke
appliances are also typically instantiated using the Net_device struct (there are some exceptions, such as Alias Interface Devices). The virtual appliance typically has a user space configuration tool to configure it. In particular, advanced fields that cannot be configured by using Ifconfig. a virtual appliance typically has a/proc interface directory, and its content verbosity depends on the design of the virtual appliance. The virtual device corresponds to a corresponding relationship that i
LOOKUP function version is for the local table and the main table, When Policy routing is supported, the logic is more complex and needs to find the routing table provided by the policy route.6, all the routing table lookup, regardless of whether the routing table is provided by policy routing, and regardless of traffic direction, is to use Fn_hash_lookup to find. Fn_hash_lookup searches for a fib_node instance that can route packets to a specific destination. Traverse the Fn_zone, and then thr
interface development, fully support OO (object oriented) design methodPersonal understandingOne-stop: an ecosystem around the spring core, such as SPRINGMVC, cloud, data, and moreLightweight: Spring is lightweight both in terms of size and overhead. The full spring framework can be published in a jar file with a size of more than 1MB. and the processing overhead required by spring is negligible. In addition, spring is non-intrusive: Typically, objects in spring applications do not depend on a
important IOC container beanfactory. Analogy: Xmlbeanfactory,filesystemxmlapplicationcontext and so on.????? -2,spring aop:spring the core modules of AOP.????? -3,spring mvc:spring MVC module.????? -4,spring jdbc/spring ORM:SPRINGJDBC Operation package.????? -5,spring transaction Processing: The enhanced transaction processing module implemented by Spring AOP.????? -6,spring Remote Call: Spring Remote Call module.3. The advantages of spring:????? -1. Spring is a non-intrusive framework whose go
standard C library. Prior to this, no standard C application was implemented.On a desktop Linux system, the first program to start is usually /sbin/init . But that's not certain. Few embedded systems will need to use the init rich initialization functionality provided (this is /etc/inittab configured). In many cases, we can invoke a simple shell script to launch the required embedded application.Back to top of pageConclusionVery similar to Linux itself, the Linux boot process is also very flexi
Code--Isolate top Waitswith Waits as (SELECT wait_type, Wait_time_ms/ +. As wait_time_s, -. * Wait_time_ms/SUM (Wait_time_ms) over () as the PCT, Row_number () over (ORDER by Wait_time_ms DESC) as RN, -. * Signal_wait_time_ms/wait_time_ms assignal_pct from sys.dm_os_wait_stats WHERE Wait_time_ms>0and wait_type not like N'%sleep%'and wait_type not like N'%idle%'and wait_type not like N'%queue%'and Wait_type not in (N'clr_auto_event', N'Request_for_deadlock_search', N'Sqltrace_buffer_flush'
to its start run. From the time that the thread collects the signals available to the resource, the thread gets CPU time and begins to use the resource location to go through. It can be thought that if the value of this property is high, it usually indicates that there is a problem with the CPU.
I/O-related waits are the most common wait (for example, Iolatch wait), for several reasons, I/O is often the most expensive resource involved in data processing operations. Also, when a query
Label:I recommend an optimization theory that uses top-down. This approach begins by analyzing the instance-level wait time, which is continuously refined through a series of steps to find out which processes/components are causing a lot of waiting in the system. Once you find these annoying processes, you can focus on optimizing them, which is not the main step of this methodology: 1. Parsing instance-level waits 2. Associating waits and Queues 3. Identify scenario 4. Refine to database/file le
distribution Networks (contents Delivery Network). Cdn= mirrored mirror+ Cache cache+ overall load balancing gslb.CDN caches static data in a Web-based site. Speed up the download of Web data content.Goal
Extensible (Scalability). Performance is extensible. Costs can be expanded.
(security).
Reliability, response, and execution (reliability, responsiveness, and performance).
Access to the static file, the first to the local DNS server request, after the iteration to the do
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