The need for memory refresh makes DRAM timing and circuits significantly more complicated than SRAM circuits, but the density and cost advantages of DRAM justify this complexity. Therefore, DRAM is used for the main memory in computers, video game consoles, graphics cards and applications requiring large capacities and low cost. As a result, data density is much lower in SRAM chips than in DRAM, and SRAM has higher price per bit. SRAM circuits require more area on a chip, because an SRAM memory cell requires four to six transistors, compared to a single transistor and a capacitor for DRAM. While a refresh cycle is occurring the memory is not available for normal read and write operations, but in modern memory this 'overhead' time is not large enough to significantly slow down memory operation.Įlectronic memory that does not require refreshing is available, called static random-access memory (SRAM). This process is conducted automatically in the background by the memory circuitry and is transparent to the user. Each memory refresh cycle refreshes a succeeding area of memory cells, thus repeatedly refreshing all the cells in a consecutive cycle. To prevent this, external circuitry periodically reads each cell and rewrites it, restoring the charge on the capacitor to its original level. As time passes, the charges in the memory cells leak away, so without being refreshed the stored data would eventually be lost. In a DRAM chip, each bit of memory data is stored as the presence or absence of an electric charge on a small capacitor on the chip. Memory refresh is a background maintenance process required during the operation of semiconductor dynamic random-access memory (DRAM), the most widely used type of computer memory, and in fact is the defining characteristic of this class of memory. Memory refresh is the process of periodically reading information from an area of computer memory and immediately rewriting the read information to the same area without modification, for the purpose of preserving the information. It seems to me that the default value will not invoke the above code.Process for preserving information in DRAM ((Timer)timerInjectedValue.getValue()).schedule(refreshTask, refreshInterval, refreshInterval)

When I decompiled a java class called DatabaseTimerPersistence.java, and found the method start(StartContext context), it has the following code: I am not very clear as to what this parameter does. It looks like a parameter that can affect performance. A low value means timers get picked up more quickly, but increase load on the database.

refresh-interval Interval between refreshing the current timer set against the underlying database.Based on the model reference ( Wildfly Model Reference ) , However, I also understand there is a parameter called 'refresh-interval' which I did not set it up. Either of the instances will invoke the scheduler at specified time, no repeating invocation was happening. I had a basic configuration that is actually working. I am testing setting EJB timer/scheduler in a wildfly cluster with two instances (#1 and #2)

Eon timer refresh interval