KR102438916B1 - Virtualization system based on container and method for expanding resource of container in virtualization system - Google Patents

Abstract

Disclosed are a container-based virtualization system capable of solving a problem in which an application program running in a container is stopped due to a lack of disk resources allocated to the container, and a method of extending the resource of a container in the virtualization system. In the disclosed virtualization system, a method of expanding a resource of a container includes: monitoring a utilization rate of a main disk resource allocated to each of a plurality of containers; and storing the write request file for the target container whose usage rate is equal to or greater than the threshold usage rate in the sub-disk.

Description

{VIRTUALIZATION SYSTEM BASED ON CONTAINER AND METHOD FOR EXPANDING RESOURCE OF CONTAINER IN VIRTUALIZATION SYSTEM}

The present invention relates to a virtualization system and a method for controlling resources in a virtualization system, and more particularly, to a container-based virtualization system and a method of extending a resource of a container in the virtualization system.

In today's representative cloud platforms, a virtualization tool called a container is provided in addition to the virtual machine, which is the previously used virtualization method. When a user requests a desired resource, the cloud platform provides the user with a container to which the requested resource is allocated.

The container-based virtualization method is an operating system level virtualization method for executing multiple isolated Linux systems on a single control host, and is also called operating system level virtualization. The container-based virtualization method provides an isolated environment for applications by combining Cgroups and Namespaces, a feature released in Linux version 2.6.24, to completely isolate the operating environment. Cgroup is an abbreviation of Control Group, which is a function of the kernel that can limit and isolate resources such as CPU, system memory, and network bandwidth of the system. It is a function of the kernel.

Existing virtualization methods that are widely used include hypervisors such as Xen and KVM, and by creating a virtual machine environment with the hypervisor and running a guest operating system on it, the host operating system and the guest operating system can be completely separated. However, this method emulates actual physical hardware, and has a disadvantage in that overhead increases.

On the other hand, the container-based virtualization method uses the method of sharing the kernel of the host operating system and isolating the application process from the rest of the system. That is, since this method creates an isolated space called a container by separating the resources used by the operating system of the host, there is no hardware emulation and almost no overhead.

There is no concept of booting and terminating a container, and starting and terminating a container is not much different from starting and terminating a process from the point of view of the operating system, so it can be handled very quickly. Representative container execution drivers include LXC (LinuX Container) and Docker.

As related prior documents, there are Korean Patent Publication No. 2018-0045347, Korean Patent Registration No. 10-1644894, and No. 10-1553532, which are patent documents.

An object of the present invention is to provide a container-based virtualization system capable of solving a problem in which an application program running in a container is stopped due to a lack of disk resources allocated to the container, and a method of extending the resource of a container in the virtualization system.

According to an embodiment of the present invention for achieving the above object, the method comprising: monitoring a utilization rate of a main disk resource allocated to each of a plurality of containers; and storing, in a sub-disk, a write request file for a target container whose usage rate is equal to or greater than a threshold usage rate.

In addition, according to another embodiment of the present invention for achieving the above object, a main disk providing a disk resource allocated in advance for each of a plurality of containers; sub disk; a resource management module for monitoring a utilization rate of disk resources allocated to each of the plurality of containers, and determining a target container whose utilization rate is equal to or greater than a threshold utilization rate; and an overlay file system for changing a storage path of a write request file for the target container from the main disk to the sub disk.

According to an embodiment of the present invention, by additionally allocating a sub-disk resource to a container and storing a write request file for a container with insufficient available disk resource in the sub-disk, interruption of an application program due to insufficient available disk resource is prevented can be

1 is a diagram for explaining a container-based virtualization system according to an embodiment of the present invention.
2 is a diagram for explaining an overlay file system according to an embodiment of the present invention.
3 is a view for explaining a container-based virtualization system according to another embodiment of the present invention.
4 is a diagram for explaining a method of extending a resource of a container in a virtualization system according to an embodiment of the present invention.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

Although the container-based virtualization method is widely used due to the advantage of inducing low overhead, when an input/output (I/O) request exceeding the storage medium allocated to the container, that is, the disk resource, occurs to the container, the Due to the lack of disk resources, an application running in the container may be stopped. That is, when a write request for data with a capacity exceeding the available disk resources for the container occurs for the container, the application program running in the container may be stopped.

Accordingly, the present invention proposes a method for expanding container resources in a container-based virtualization environment. Since the resource allocated to the container cannot be adjusted while the container is created, an embodiment of the present invention uses a physical resource called a sub-disk to support resource expansion of the container even when the container is created. Basically, the disk resource allocated to the container is supported from the main disk, and when the container resource needs to be expanded later, the auxiliary disk resource is additionally supported by the container. In this case, the input/output (I/O) routine is changed from the main disk to the sub disk.

The sub-disk resource is a temporarily provided resource, and data stored in the sub-disk may then be stored in the main disk. It is preferable that the input/output speed of the sub-disk is faster than the input/output speed of the main disk so that data stored in the sub-disk can be quickly moved to the main disk thereafter.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram for explaining a container-based virtualization system according to an embodiment of the present invention, and FIG. 2 is a diagram for explaining an overlay file system according to an embodiment of the present invention.

Referring to FIG. 1 , a virtualization system according to an embodiment of the present invention includes a main disk 110 , a sub disk 120 , a resource management module 130 , and an overlay file system 140 .

The main disk 110 provides pre-allocated disk resources for each of the plurality of containers 151 and 152 . The main disk 110 may be an HDD or a SATA SSD as an embodiment, and the sub disk 120 may be an NVMe SSD having a faster input/output speed than the main disk 110 .

The resource management module 130 monitors the usage rate of the main disk resource allocated to each of the plurality of containers, and determines a target container whose usage rate is equal to or greater than a threshold usage rate. In other words, the resource management module 130 determines a target container whose residual resource amount is less than or equal to a threshold residual amount among the resources of the main disk allocated to the container.

For example, the threshold usage rate may be set to 90 to 95%. That is, here, the target container is a container whose main disk resource usage rate is approaching 100%, and when an additional write request occurs for such a container, the application program running in the container may be stopped, so the resource management module 130 is Monitor these target containers.

The overlay file system 140 changes the storage path of the write request file for the target container from the main disk to the sub disk. The overlay file system 140 may receive a flag signal for the target container from the resource management module 130 to change the storage path of the write request file for the target container.

The resource management module 130 may partition and mount the sub-disk so that the write request file for the target container can be stored in the sub-disk, and each partition is assigned to the container. As an embodiment, the resource management module 130 partitions the sub disks according to the number of a plurality of containers, and the partitioned capacity may be determined according to the amount of main disk resources allocated to each container.

For example, if the number of the plurality of containers is 10, the resource management module 130 may create 10 partitions for the sub-disk 120 , and the partition capacity allocated to the container having a high main disk resource amount is the same as the main disk resource amount. It may be larger than the partition capacity allocated to the lower container.

The upper directory of the overlay file system includes a directory for write request files stored in the sub disk so that data can be stored in a partition assigned to each container.

An overlay file system is a type of union file system, and it is a file system that mounts multiple directories at a single directory point to look like a single integrated directory. As shown in FIG. 2 , the overlay file system is composed of a merged directory 141 , an upper directory 142 , and a lower directory 143 located in different layers.

The sub-directory 143 is a read-only directory, in which a read-only file is disposed, and corresponds to an image layer in a container-based virtualization system. The upper directory 142 is a write directory, in which new or updated files are placed, and corresponds to a container layer in a container-based virtualization system. The merge directory 141 is a directory shown to the user, and the upper directory 142 and the lower directory 143 are shown to the user in a merged form.

Since the embodiment of the present invention stores data not only on the main disk 110 but also on the sub-disk 120 , the overlay file system 140 according to the embodiment of the present invention is located in the upper directory 142 in the main disk. In addition to the first directory 1421 for the write request file stored in 110 , the second directory 1422 for the write request file stored in the sub disk 120 is further included. The second directory 1422 may be disposed above the first directory 1411 .

The overlay file system 140 changes the storage path of the write request file in response to the flag signal. In a state where the resource usage rate of the target container is low, the write-requested file file2 is stored in the main disk 110 , and the write-requested file file2 is disposed in the first directory 1421 . Thereafter, the write-requested file file4 in a state where the resource usage rate of the target container is high is stored in the sub-disk 120 , and the write-requested file file4 is disposed in the second directory 1422 .

If a portion of the data of the write request file for the target container is already stored in the main disk 110 , some of the data stored in the main disk 110 is moved to the sub disk 120 . That is, when a part of the data of the write request file is already stored in the main disk 110 and the write request file needs to be updated and stored when the disk resource usage rate is equal to or higher than the threshold usage rate, the data stored in the main disk 110 is A portion is moved to the sub-disk 120 , and the entire data of the write request file is stored in the sub-disk 120 . In addition, since the write request file is generated in the second directory 1422 , the user can check the write request file through the merge directory 141 .

As described above, according to an embodiment of the present invention, by additionally allocating a sub-disk resource to a container, and storing a write request file for a container with insufficient available disk resource in the sub-disk, Interruptions can be avoided.

Meanwhile, according to another embodiment of the present invention, the resource management module 130 partitions the sub-disks when the number of containers is greater than or equal to the threshold number in order to increase the utilization rate of the sub-disks, and the threshold number may be determined according to the capacity of the sub-disks. have. When the number of containers is very small and the sub-disk is partitioned according to the number of containers, too many resources are allocated to each container and inefficiency of resource use may result. In this case, subdisks can be partitioned. In addition, the threshold number may be determined in proportion to the capacity of the sub-disk.

3 is a view for explaining a container-based virtualization system according to another embodiment of the present invention.

Docker Demon (310) creates and manages containers. For each container, a first directory 311 in which data is stored in the main disk 340 and a second directory 312 in which data is stored in the sub disk are allocated. The first directory 311 may be allocated by the Docker daemon 310 , and the second directory 312 may be allocated by the second module 330 .

The first module 320 communicates with the Docker daemon 310 through a system call, receives the location path and quota ID of the container from the Docker daemon 310, and sets the location path and quota ID of the container to the second It passes to module 330 . The quota is a function used to limit resources to users in the Linux system, and the main disk resource allocated to the container may be identified through the quota ID allocated to the container.

The second module 330 monitors the main disk resource usage rate of the container and partitions the sub disk 350 . Each of the partitions of the sub-disk 350 is mounted in each of the second directories 312 . The second module 330 transmits a flag signal for a target container whose resource usage rate is equal to or greater than the threshold usage rate to the overlay file system 360 . The second module 330 may check the main disk resource usage of the container through the location path of the container, and check the main disk resource usage rate of the container through the main disk resource usage and the quota ID.

The overlay file system 360 mounts the parent directory and the sub-directory to the merge directory. The upper directory includes first and second directories 311 and 312 , and each directory is mapped to an inode and stored in a memory.

The overlay file system 360 checks whether a write-requested file exists in an upper directory or a lower directory. If the file requested to be written exists in the upper directory, the updated write request file is placed in the upper directory. If the file requested to be written exists in the lower directory, the sub-directory is copied to the upper directory. If the file requested to be written does not exist in the upper directory or subdirectory, a new file is created in the upper directory.

4 is a diagram for explaining a method of extending a resource of a container in a virtualization system according to an embodiment of the present invention.

Referring to FIG. 4 , the virtualization system according to an embodiment of the present invention monitors ( S410 ) the usage rate of the main disk resource allocated to each of a plurality of containers, and sends a write request file to a target container whose usage rate is equal to or greater than the threshold usage rate. It is stored in the sub disk (S420).

In step S420, the virtualization system partitions the sub-disk according to the number of containers, and stores the write request file in the partition of the sub-disk allocated to the target container. The partitioned capacity may be determined according to the amount of main disk resource allocated to each container.

In addition, in step S420, the virtualization system stores the write request file in the sub-disk by using the overlay file system, and the upper directory of the overlay file system includes a directory for the write request file stored in the sub-disk. The write request file is placed in the directory for the write request file, and if the write request file is placed in the directory for the main disk, the write request file stored in the main disk is copied to the sub disk. That is, when a portion of data of the write request file is already stored in the main disk, the virtualization system moves a portion of data stored in the main disk to the sub disk.

According to an embodiment, the virtualization system according to an embodiment of the present invention provides, to the user terminal of the target container, occurrence information of an event in which the usage rate is greater than or equal to the threshold usage rate (S430), so that the user increases the main disk resource for the target container. can guide you.

And when the user requests an increase in the main disk resource allocated to the target container, the virtualization system may increase the amount of the main disk resource allocated to the target container according to the request of the user terminal ( S440 ). Then, the target system moves the write request file stored in the sub disk to the main disk (S450).

When the target container is regenerated after the termination, the user may be provided with a service through the target container to which the increased amount of the main disk resource is allocated.

The technical contents described above may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiments, or may be known and available to those skilled in the art of computer software. Examples of the computer-readable recording medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic such as floppy disks. - includes magneto-optical media, and hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. A hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, in the present invention, specific matters such as specific components, etc., and limited embodiments and drawings have been described, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments. , various modifications and variations are possible from these descriptions by those of ordinary skill in the art to which the present invention pertains. Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims described below, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (12)

monitoring a utilization rate of a main disk resource allocated to each of a plurality of containers; and
Storing a write request file for a target container whose usage rate is greater than or equal to a threshold usage rate in a sub-disk,
The step of saving the write request file to the sub disk is
partition the sub disk according to the number of the plurality of containers, and store the write request file in a partition allocated to the target container;
The partitioned capacity is determined according to the amount of main disk resources allocated to each of the containers,
The step of saving the write request file to the sub disk is
When a part of the data of the write request file is already stored in the main disk, a part of the data stored in the main disk is moved to the sub-disk.
How to extend the resources of containers in a virtualization system.
delete The method of claim 1,
The step of saving the write request file to the sub disk is
Using the overlay file system, the write request file is stored in the sub disk,
The upper directory of the overlay file system includes a directory for a write request file stored in the sub disk
How to extend the resources of containers in a virtualization system.
delete The method of claim 1,
providing, to the user terminal of the target container, occurrence information of an event in which the usage rate is equal to or greater than a threshold usage rate;
increasing the amount of main disk resources allocated to the target container according to the request of the user terminal; and
moving the write request file stored in the sub disk to the main disk
How to extend the resources of the container in the virtualization system further comprising.
The method of claim 1,
The I/O speed of the sub disk is
faster than the input/output speed of the main disk
How to extend the resources of containers in a virtualization system.
a main disk providing pre-allocated disk resources for each of the plurality of containers;
sub disk;
a resource management module for monitoring a utilization rate of disk resources allocated to each of the plurality of containers, and determining a target container whose utilization rate is equal to or greater than a threshold utilization rate; and
and an overlay file system for changing a storage path of a write request file for the target container from the main disk to the sub disk,
the resource management module partitions the sub-disk according to the number of the plurality of containers, and stores the write request file in a partition allocated to the target container;
The partitioned capacity is determined according to the amount of main disk resources allocated to each of the containers,
When a portion of the data of the write request file is already stored in the main disk, some of the data stored in the main disk is moved to the sub disk
Container-based virtualization system.
delete 8. The method of claim 7,
The resource management module is
When the number of containers is greater than or equal to a threshold number, the sub-disk is partitioned,
The threshold number is determined according to the capacity of the sub-disk.
Container-based virtualization system.
8. The method of claim 7,
The resource management module is
providing a flag signal for the target container to the overlay file system;
In the upper directory of the overlay file system,
A directory for a write request file stored in the sub disk is included.
Container-based virtualization system.
delete 8. The method of claim 7,
The main disk is HDD or SATA SSD,
The sub disk is an NVMe SSD
Container-based virtualization system.

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