Off-heap memory leak. I'm not sure if it's a grpc-spring problem or a netty problem.

[hakusai22]

Using top -c to check RES memory usage, it was 1.2g on Friday and rose to 1.5g on Monday. Using pmap to check 1539536kb (1.5g), and turning on NMT to check jcmd -p VM.native_memory detail, the total committed memory is 1152483kb (1g). The difference is 377MB. These are all off-heap memories that JVM cannot monitor. The off-heap memory block data at the memory address 00007xxxx has increased, and it is suspected to be an off-heap memory leak. Checking the dump file, it is found that the classes related to off-heap memory are io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueue and io.grpc.netty.shaded.io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueue

Below are the memory leak data analyzed by grpc version, netty version and mat tool

        <dependency>
            <groupId>io.grpc</groupId>
            <artifactId>grpc-protobuf</artifactId>
            <version>1.53.0</version>
        </dependency>

        <grpc.spring.version>2.14.0.RELEASE</grpc.spring.version>

            <!-- grpc -->
            <dependency>
                <groupId>net.devh</groupId>
                <artifactId>grpc-client-spring-boot-starter</artifactId>
                <version>${grpc.spring.version}</version>
            </dependency>
            <dependency>
                <groupId>net.devh</groupId>
                <artifactId>grpc-server-spring-boot-starter</artifactId>
                <version>${grpc.spring.version}</version>
            </dependency>

• io.netty.buffer.PoolThreadCache$SubPageMemoryRegionCache

• io.netty.util.internal.shaded.org.jctools.queues.MpscArrayQueue