Definition: What Is a Memory Bottleneck?
The term “bottleneck” refers to any restrictive element that limits the system’s performance.
Memory bottleneck describes a computing state where a system’s processing capability is limited due to the RAM being insufficient, not being fast enough, or a memory leak.
Why Should You Care About Memory Bottlenecks?
RAM is the temporary memory storage for holding data about to be processed. The amount of RAM determines the processing speed of the system. Thus if the RAM doesn’t have enough memory due to insufficient memory allocated, the processor wouldn’t receive data fast enough, and the data flow from the RAM to the CPU will suffer. The CPU, on the other hand, handles almost every operation within the system. Thus there will be a slowdown, decline in performance, or a halt if, for any reason, the CPU is not getting data fast enough.
The RAM’s inefficiency in processing and quickly transferring data to the CPU causes a memory bottleneck. Memory bottlenecks negatively and significantly impact the performance of your system. Primarily because it leads to high CPU usage, and processes can’t run at their most optimized. This affects and decreases the efficiency and speed at which your system carries out various tasks and operations, which can further result in a slowdown or halt of operations.
What Causes Memory Bottlenecks?
Memory bottlenecks can occur due to several reasons. A few of these include:
- Insufficient RAM: Here, the system doesn’t have enough physical memory to support all the active processes and applications. This results in the operating system (OS) offloading storage to disk storage (SSDs and HDDs), significantly slowing down the system’s performance. For Linux, this, however, only occurs if Swap is enabled.
- Out of memory: This occurs when the computing system has exhausted all of its available physical memory and cannot allocate any more memory for new processes or applications. So the system tries to make room for these new processes by swapping memory pages to the hard disk. If it can’t do it, it terminates these processes.
- Malfunctioning memory, disk, or computer system: This cuts across memory errors, disk failures, and driver issues. These defects and outdated drivers can cause a significant increase in disk I/O operations, memory leaks, or inefficient memory usage, leading to a memory bottleneck.
- Timeouts while waiting for memory: A timeout occurs when the system requests for memory resources, but it takes too long to be available. This can be due to insufficient memory, fragmented memory, high disk I/O, or slow memory access times.
- Systems process: Some computing processes and applications process high volumes of information; thus, they can get memory-intensive programs. These processes tend to cause a strain on the system’s available memory if left running in the background when not in use. When this happens, an out-of-memory or insufficient RAM state kicks in, causing a memory bottleneck.
- Incorrectly configured applications, memory, or mismatched memory modules: When an application or memory isn’t configured correctly, substantially more memory than is required frequently gets used. As a result, the system exhausts its memory due to heavy usage, affecting stability and performance. In addition, when memory modules are mismatched, the system may not access memory properly, creating a memory bottleneck. This is because the memory modules may run at different rates or latencies.
- Memory leaks: A memory leak is a continuous increase in shared resources—memory—by the computing process because it doesn’t free up previously allocated memory that it doesn’t need. This happens because of a malfunctioning memory, wrongly configured applications, or source code error. As memory usage continues to grow, eventually, it reaches a point where all available memory has been consumed, thus causing a memory bottleneck.
How to Find Memory Bottlenecks?
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Finding memory bottlenecks involves analyzing memory usage to identify processes that are consuming excessive amounts of memory and slowing down the performance of your computing system. This can be achieved in two ways:
Monitoring the page faults counter
The page fault gives information regarding the available byte (available physical memory) and committed bytes (available virtual address that wasn’t readily available in RAM). Other details include pages/sec (number of pages requested but not readily available in RAM) and page faults/sec (number of virtual pages not found in memory). It’s also a good idea to occasionally check on the paged pool (the system memory used to write to disk when not in use) and nonpaged pool memory (the system memory for things that can’t be written to disk).
Using an application performance monitoring (APM) tool
These tools can provide information on memory usage by process, memory usage history, and memory usage graphs, which can help you identify these memory-intensive processes in real time. However, regardless of the tool used, the means of choice should give you real-time monitoring of memory usage, display memory usage by process, notify you of any unusual memory usage, and memory dumps analysis for troubleshooting purposes.
- System monitor utility tools like Windows Task Manager (Windows), Activity Monitor (macOS), top (Linux), and Process Explorer (Windows). Each of them provides a different level of detail and functionality. You can also kill any high RAM utilization process from these tools and use the memory errors to find out the cause of the memory bottleneck. For example, is it due to a sudden unexpected CPU spike or an increase in query execution time.
- Cross-platform APM like Nagios, JProfiler, and Sematext Cloud. These tools allow you to collect and report metrics on the system’s performance and resource utilization across your whole stack’s process in real-time. By monitoring the CPU, memory, and disk usage, one can get the big picture of their past and present utilization for capacity planning and easy troubleshooting against memory bottlenecks.
How to Fix a Memory Bottleneck?
Before you can fix any bottleneck issues, you need first to identify the process that is consuming more memory than it should. Then you can increase the capacity of your system by optimizing the cache usage or replacing the existing physical memory (RAM) with faster RAM tol fix the memory bottleneck issues. Unfortunately, there is a maximum cache limit that a system’s OS and hardware can manage.
When the situation is much more complicated, other ways, such as
- Program fix. This is required when the root cause is a memory leak caused by a programming error in a program that prevents it from letting go of the memory it isn’t using.
- By increasing the paging file size (virtual memory). This memory is typically only used to write codes and data that are no longer active on disk. However, when there is a bottleneck, the system uses it to write and retrieve data more frequently. Increasing the size of the paging file aims to lessen the effect of this slow, resource-intensive process.
- By removing unnecessary drivers, protocols, and display settings: This helps by freeing up memory resources used by these components. In addition, by removing the unnecessary drivers, protocols, and display settings, you respectively reduce the number of system calls, data, and active display settings the OS can make, process, and use.
- Adding more physical memory (RAM): The idea of increasing RAM is to provide the system access to more memory. Thus, improving memory utilization, reducing swapping and the likelihood of memory bottlenecks and improving overall performance. Inefficient algorithms, memory leaks, fragmentation, and other variables can still affect performance. This fix is also limited by the maximum amount that the computer hardware and the OS can handle. Therefore, this isn’t alway a guaranteed way.
How to Prevent Memory Bottlenecks?
While solutions like adding more physical memory (RAM) can help fix memory bottlenecks, here are a few tips to prevent them.
- Proper memory usage/management: this involves properly allocating and releasing memory that is no longer required. You can accomplish this by dynamically (`malloc()` in C) allocating memory whenever possible rather than statically (using global or static variables). Utilizing a deallocation function, pool allocators (custom memory allocators), or RAII (Resource Acquisition Is Initialization) are a few other methods. For example, RAII is a programming idiom that automatically frees resources when they go out of scope.
- Optimizing the cache usage: The goal here is to minimize cache misses, which occur when the processor tries to access data in the cache and fails, leading to slower access to the main memory. Here, strategies such as using optimized cache-friendly data structures for cache usage, avoiding false sharing, and data locality are employed.
- Stopping resource-intensive background processes and overclocking: Shutting down resource-heavy background processes and overclocking your CPU and RAM. However, it is essential to know that overclocking your CPU, which means configuring it to work harder, can damage the CPU.
- Revaluating applications and processes: Here, the goal is to examine the applications and processes running to determine if memory is being used efficiently. To do this, the OS allocates memory to running processes based on their priority (process prioritization), undergoes application optimization strategies, and limits the amount of memory available to individual applications or processes. Furthermore, you can use task schedulers to ensure memory-intensive processes run when memory is most available.
- Avoiding memory fragmentation: Fragmentation handles allocation and deallocation just like memory leak does. Occasionally restarting the program, preallocating memory upfront, or changing the system allocator are a few ways to avoid fragmentation. These methods will, however, only delay the inevitable. The best option is to upgrade to more physical memory (RAM) or monitor your systems with the right set of tools.
- Monitoring applications: Your APM tools are used for this. By identifying memory leaks and inefficient memory utilization, these tools help decrease the incidence of memory bottlenecks. In addition, these tools can help you understand memory usage more thoroughly.
Detecting Memory Bottlenecks with Sematext
Sematext Monitoring is a full-stack monitoring solution allow you to monitor key metrics your infrastructure, including memory, of course. You get out-of-the-box dashboards that you can easily customize to show the resources you are interested in, such as those related to memory usage, as well as pre-configured alerts you can modify to get you started quickly.
Sematext’s powerful alerting engine with anomaly detection and alert scheduling helps you discover memory-related issues more quickly or even identify potential issues before they arise. As soon as it detects irregularities, the tool notifies you via the notification channel of your choice. Memory bottlenecks can be automatically detected with a threshold or an anomaly alert on the system’s RAM usage. JVM heap, garbage collection, etc. Setting an alert on the RAM usage will allow you to get real-time alerts on memory bottlenecks as they occur.
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