CN110955460B - Service process starting method and device, electronic equipment and storage medium - Google Patents

Abstract

The embodiment of the application provides a service process starting method, a device, electronic equipment and a storage medium, which are applied to a distributed application program coordination process of nodes in a distributed system, wherein each node comprises a distributed application program coordination process and at least one service process, the distributed application program coordination process stores information of configuration items of each service process, the distributed application program coordination process receives a first query request, and the first query request is request information for acquiring the configuration items of any service process when the service process is started; inquiring information of the configuration items corresponding to the first inquiry request from the stored information of the configuration items according to the first inquiry request; and sending the queried information of the configuration items to the service process so that the service process is started according to the information of the configuration items. Each service process can directly acquire configuration items from the distributed application program coordination process, so that the number of configuration files stored in the distributed system is reduced, and further resource waste is reduced.

Description

A service process starting method, device, electronic device and storage medium

Technical field

The present invention relates to the field of distributed storage, and in particular to a service process starting method, device, electronic device and storage medium.

Background technique

In a distributed system, when a service process starts, it needs to load the startup configuration item information required by the service process. Among them, the startup configuration items of the service process can include the port number of the service, the maximum number of concurrencies, the number of worker threads, the cache size, etc.

In related technologies, it is usually necessary to obtain the configuration file of each service process in advance in a distributed system. The configuration file of each service process contains information about all startup configuration items that need to be loaded when the service process starts. In this way, during startup When any service process is started, by reading the configuration file of the service process, the startup configuration items required by the service process can be loaded, thereby starting the service process.

However, since the configuration files of each process need to be obtained in advance, when the number of processes in the distributed system is large, a large number of configuration files will be stored in the distributed system, and there is also a large amount of duplicate information in the configuration files. Leading to a waste of resources within the distributed system.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a service process startup method, device, electronic device and storage medium to reduce the number of configuration files stored in a distributed system, thereby reducing resource waste in the distributed system. The specific technical solutions are as follows:

Embodiments of the present invention provide a method for starting a service process, which is applied to a distributed application coordination process of a node in a distributed system. The node includes a distributed application coordination process and at least one service process. The distributed application coordination process The application coordination process stores information about the configuration items of each service process. The method includes:

Receive a first query request, which is request information for obtaining configuration items of any of the service processes when they are started;

According to the first query request, query the information of the configuration item corresponding to the first query request from the stored configuration item information;

The queried information about the configuration item corresponding to the first query request is sent to the service process, so that the service process is started according to the information about the configuration item corresponding to the first query request.

Optionally, the method also includes:

Receive updated information for any of the configuration items;

Update the stored configuration item according to the update information;

Synchronize the updated configuration item to the at least one service process.

Optionally, the method also includes:

Receive the registration information of any of the service processes;

Synchronizing the updated configuration items to the at least one service process includes:

According to the registration information, the updated configuration item information is sent to the at least one service process, so that any of the service processes updates its configuration item based on the updated configuration item information.

Optionally, synchronizing the updated configuration items to the at least one service process includes:

Receive a second query request, which is request information sent by any of the service processes according to a preset time interval for querying its configuration items;

According to the second query request, query the information of the configuration item corresponding to the second query request from the stored information of the configuration item;

Send the queried information on the configuration item corresponding to the second query request to the service process, so that the service process performs the configuration on the configuration item based on the information on the configuration item corresponding to the second query request. renew.

Embodiments of the present invention also provide a service process starting device, which is applied to the distributed application coordination process of a node in a distributed system. The node includes a distributed application coordination process and at least one service process. The distribution process The application coordination process stores information about the configuration items of each service process, and the device includes:

A receiving module, configured to receive a first query request, which is a request information for obtaining configuration items of any service process when it is started;

A query module, configured to query the information of the configuration item corresponding to the first query request from the stored information of the configuration item according to the first query request;

A sending module, configured to send the queried information about the configuration item corresponding to the first query request to the service process, so that the service process is started according to the information about the configuration item corresponding to the first query request.

Optionally, the device also includes:

An update module, configured to receive update information for any of the configuration items; update the stored configuration item according to the update information; and synchronize the updated configuration item to the at least one service process.

Optionally, the receiving module is also used to receive registration information of any of the service processes;

The update module is also configured to send updated configuration item information to the at least one service process according to the registration information, so that the at least one service process can, according to the updated configuration item information, Update its configuration items.

Optionally, the update module is also used for:

Receive a second query request, which is request information sent by any of the service processes according to a preset time interval for querying its configuration items;

According to the second query request, query the information of the configuration item corresponding to the second query request from the stored information of the configuration item;

Send the queried information on the configuration item corresponding to the second query request to the service process, so that the service process performs the configuration on the configuration item based on the information on the configuration item corresponding to the second query request. renew.

An embodiment of the present invention also provides an electronic device, including a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory complete communication with each other through the communication bus;

Memory, used to store computer programs;

The processor is used to implement any of the above service process starting methods when executing the program stored in the memory.

Embodiments of the present invention also provide a computer-readable storage medium. A computer program is stored in the computer-readable storage medium. When the computer program is executed by a processor, any one of the above service process starting methods is implemented.

Embodiments of the present invention also provide a computer program product containing instructions that, when run on a computer, cause the computer to execute any one of the above service process starting methods.

The service process startup method and device provided by embodiments of the present invention are applied to the distributed application coordination process of nodes in a distributed system. Each node includes a distributed application coordination process and at least one service process. The distributed application program The coordination process stores information about the configuration items of each service process. In this method, the distributed application coordination process receives the first query request. The first query request is a request for obtaining the configuration items of any service process when it is started. information; query the information of the configuration item corresponding to the first query request from the stored configuration item information according to the first query request; send the queried information of the configuration item corresponding to the first query request to the service process , so that the service process starts based on the information of the configuration item. In this way, through the configuration items of each server process stored in the distributed application coordination process, each service process can directly obtain the required configuration items from the distributed application coordination process, without the need to store the corresponding configuration items for each service process. Configuration files, thereby reducing the number of configuration files stored in the distributed system, thereby reducing the waste of resources in the distributed system. Of course, implementing any product or method of the present invention does not necessarily require achieving all the above-mentioned advantages simultaneously.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic flowchart of a service process starting method provided by an embodiment of the present invention;

Figure 2 is a schematic flow chart of another service process starting method provided by an embodiment of the present invention;

Figure 3 is a schematic structural diagram of a service process starting device provided by an embodiment of the present invention;

Figure 4 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

In related technologies, it is usually necessary to obtain the configuration file of each service process in advance in a distributed system. The configuration file of each service process contains information about all startup configuration items that need to be loaded when the service process starts. In this way, during startup When any service process is started, by reading the configuration file of the service process, the startup configuration items required by the service process can be loaded, thereby starting the service process.

However, since the configuration files of each process need to be obtained in advance, when the number of processes in the distributed system is large, a large number of configuration files will be stored in the distributed system, and there is also a large amount of duplicate information in the configuration files. Leading to a waste of resources within the distributed system.

The following is an overall description of the service process starting method provided by the embodiment of the present invention. This method is applied to the distributed application coordination process of the node in the distributed system. The node includes a distributed application coordination process and at least one service process. , the distributed application coordination process stores information about the configuration items of each service process. The method includes:

Receive the first query request, which is the request information used to obtain the configuration items of any service process when it is started;

According to the first query request, query the information of the configuration item corresponding to the first query request from the stored configuration item information;

The queried information about the configuration item corresponding to the first query request is sent to the service process, so that the service process is started according to the information about the configuration item.

As can be seen from the above, the service process startup method provided by the embodiment of the present invention uses the configuration items of each server process stored in the distributed application coordination process. Each service process can directly obtain the required configuration from the distributed application coordination process. It is not necessary to store corresponding configuration files for each service process, thereby reducing the number of configuration files stored in the distributed system, thereby reducing the waste of resources in the distributed system.

The service process startup method provided by the embodiment of the present invention is described in detail below through specific embodiments. This method is applied to the distributed application coordination process of the node in the distributed system. The node includes a distributed application coordination process and at least A service process, the distributed application coordination process stores information about the configuration items of each service process.

The distributed application coordination process is a distributed coordinated system that can be deployed in various nodes of the distributed system. The distributed application coordination process can store information about the configuration items of each service process directly through interaction with the user, or it can also store the configuration items of each service process through communication with other devices in the distributed system. Information. For example, the distributed application coordination process can be the zookeeper process.

The configuration items may include the number of threads, cache size, port number, maximum queue length, etc., which are not limited in this embodiment of the present invention.

For example, in the distributed application coordination process, the information of multiple configuration items may be stored in the form of a database or in the form of a linked list, which is not limited in this embodiment of the present invention. Among them, the value of each configuration item is unique.

As shown in Figure 1, it is a schematic flow chart of a service process startup method provided by an embodiment of the present invention. This method is applied to the distributed application coordination process of nodes in a distributed system and includes the following steps:

S101: Receive the first query request, which is the request information used to obtain the configuration items of any service process when it is started.

The first query request may be sent by the service process to the distributed application coordination process after receiving the startup instruction. The startup instruction may be obtained through interaction between the node and the user, or it may be a distributed system Sent to this node by other nodes in , in addition, it can also be generated by this node according to preset rules.

After receiving the startup instruction, the service process can generate a first query request based on the configuration items it needs to obtain when it starts. That is to say, the first query request includes the configuration items needed when the service process starts. In this way, the distributed application coordination process can determine which configuration item information the service process needs to obtain based on the first query request.

S102: According to the first query request, query the information of the configuration item corresponding to the first query request from the stored information of the configuration item.

In the embodiment of the present invention, after the distributed application coordination process receives the first query request, it can analyze the first query request to determine the startup configuration items required when the service process is started, and then, from the multiple stored configurations In the item information, query the information of these startup configuration items.

In a distributed system, there may be multiple service processes. Each service process may have one or more configuration items. The configuration items of different service processes may be the same or different. In this way, the first query request generated by each service process is also different.

In the distributed application coordination process, the configuration item information of each service process is stored. In this way, each service process can obtain its own configuration item information from the distributed application coordination process through the first query request. .

S103: Send the queried information about the configuration item corresponding to the first query request to the service process, so that the service process is started based on the information about the configuration item.

After the service process obtains the information of its configuration items, it can be started and run according to the information of the configuration items, thereby providing corresponding services to users. In the embodiment of the present invention, during the startup process of the service process, the information of the configuration items can be obtained directly from the distributed application coordination process, without obtaining the information of the configuration items from the pre-obtained configuration file. That is to say, a On the one hand, it can reduce the number of configuration files stored in the distributed system. On the other hand, the information of any configuration item only needs to be set in the distributed application coordination process, and does not need to be stored in each service process separately. Corresponding multiple configuration files, thereby reducing resource waste in distributed systems.

As shown in Figure 2, it is a schematic flow chart of another service process startup method provided by an embodiment of the present invention, which is applied to the distributed application coordination process of nodes in a distributed system. In the service process startup method shown in Figure 1 Basically, the service process startup method also includes:

S104: Receive update information for any configuration item.

For example, update information for any configuration item can be generated through interaction with the user. When the user modifies any configuration item, update information for the configuration item can be generated based on the user's modification content.

S105: Update the stored configuration item according to the update information.

After receiving the update information, the distributed application coordination process can search for the configuration item corresponding to the update information in the stored configuration items, and then update the stored configuration item. In this way, when any service process requests its configuration items from the distributed application coordination process, it can directly obtain the updated configuration items without having to update its configuration items after startup, thus making the distributed system Run more efficiently.

S106: Synchronize the updated configuration items to at least one service process.

After the distributed application coordination process updates the stored configuration items, the updated configuration items can be synchronized to at least one service process. In other words, the service process can directly synchronize the updated configuration items from the distributed application coordination process without re-obtaining the information of the configuration items in the updated configuration file through restarting. In this way, the distributed system It is simpler to update configuration items and take effect faster, thus improving the efficiency of configuration item updates in distributed systems.

For example, in one implementation, the distributed application coordination process can receive the registration information of any service process. In this way, after updating the stored configuration items, the distributed application coordination process can receive the registration information based on the received configuration items. Registration information, sending the updated configuration item information to the service process that has sent the registration information. Furthermore, the service process can update its own configuration items based on the updated configuration item information returned by the distributed application coordination process.

In another implementation, the service process can send a second query request to the distributed application coordination process at a preset time interval after being started, where the second query request is used to query the configuration items of any service process. request information. After receiving the second query request, the distributed application coordination service can query the information of the configuration item corresponding to the second query request from the stored configuration item information according to the second query request, and then query the The information of the configuration item corresponding to the second query request is sent to the service process. In this way, the service process can update its configuration item based on the information of the configuration item corresponding to the second query request.

The second query request may also be request information for querying a part of the configuration items of the service process. For example, the service process may only query one or more configuration items with a higher importance level from the distributed application coordination process without Information about all startup configuration items needs to be queried, which can reduce the amount of data that needs to be transmitted, thereby further reducing the waste of resources in the distributed system.

By sending the second query request by the service process, the service process can monitor the feedback of the distributed application coordination process after each second query request is sent. If no distributed application coordination is received for a long period of time, process feedback, it is judged that the communication between the current service process and the distributed application coordination process has failed, and then measures such as resending the second query request or reporting an error are taken to reduce the number of second query requests or distributed applications sent by the service process. The running error of the distributed system is caused by the loss of the configuration item information corresponding to the second query request returned by the program coordination process.

In addition, in one implementation, the above two synchronization methods of configuration items to be updated can also be applied at the same time, that is, the distributed application coordination process can send the updated configuration item information based on the received registration information. to the service process. At the same time, the service process can send a second query request to the distributed application coordination process according to a preset time interval after being started. In this way, running errors of the distributed system caused by the loss of the second query request sent by the service process or the information of the configuration item corresponding to the second query request returned by the distributed application coordination process can be further reduced.

As can be seen from the above, the service process startup method provided by the embodiment of the present invention uses the configuration items of each server process stored in the distributed application coordination process. Each service process can directly obtain the required configuration from the distributed application coordination process. It is not necessary to store corresponding configuration files for each service process, thereby reducing the number of configuration files stored in the distributed system, thereby reducing the waste of resources in the distributed system.

Corresponding to the above service process starting method, the embodiment of the present application also provides a service process starting device, which is applied to the distributed application coordination process of the node in the distributed system, and the node includes a distributed application coordination process. process and at least one service process. The distributed application coordination process stores information about the configuration items of each service process.

As shown in Figure 3, it is a schematic structural diagram of a service process starting device provided by an embodiment of the present invention. The device is applied to the distributed application coordination process of nodes in a distributed system, and includes:

The receiving module 301 is used to receive the first query request, which is the request information used to obtain the configuration items of any service process when it is started;

The query module 302 is configured to query the information of the configuration item corresponding to the first query request from the stored configuration item information according to the first query request;

The sending module 303 is configured to send the queried information about the configuration item corresponding to the first query request to the service process, so that the service process is started based on the information about the configuration item corresponding to the first query request.

In one implementation, the device further includes:

An update module (not shown in the figure) is used to receive update information for any configuration item; update the stored configuration item according to the update information; and synchronize the updated configuration item to at least one service process.

In one implementation, the receiving module 301 is also used to receive the registration information of any service process;

The update module is also configured to send updated configuration item information to at least one service process based on the registration information, so that at least one service process updates its configuration item based on the updated configuration item information.

In one implementation, the update module is also used for:

Receive a second query request, which is request information sent by any service process at a preset time interval for querying its configuration items;

According to the second query request, query the information of the configuration item corresponding to the second query request from the stored information of the configuration item;

The queried information about the configuration item corresponding to the second query request is sent to the service process, so that the service process updates the configuration item according to the information about the configuration item corresponding to the second query request.

It can be seen from the above that the service process starting device provided by the embodiment of the present invention uses the configuration items of each server process stored in the distributed application coordination process. Each service process can directly obtain the required configuration from the distributed application coordination process. It is not necessary to store corresponding configuration files for each service process, thereby reducing the number of configuration files stored in the distributed system, thereby reducing the waste of resources in the distributed system.

An embodiment of the present invention also provides an electronic device, as shown in Figure 4, including a processor 401, a communication interface 402, a memory 403, and a communication bus 404. The processor 401, the communication interface 402, and the memory 403 communicate through the communication bus 404. complete mutual communication,

Memory 403, used to store computer programs;

When the processor 401 is used to execute the program stored in the memory 403, it implements the following steps:

Receive the first query request, which is the request information used to obtain the configuration items of any service process when it is started;

According to the first query request, query the information of the configuration item corresponding to the first query request from the stored configuration item information;

The queried information about the configuration item corresponding to the first query request is sent to the service process, so that the service process is started according to the information about the configuration item.

The communication bus mentioned in the above-mentioned electronic equipment may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into address bus, data bus, control bus, etc. For ease of presentation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

The communication interface is used for communication between the above-mentioned electronic devices and other devices.

The memory may include random access memory (Random Access Memory, RAM) or non-volatile memory (Non-Volatile Memory, NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located far away from the aforementioned processor.

The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (Network Processor, NP), etc.; it can also be a digital signal processor (Digital SignalProcessing, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, and discrete hardware components.

It can be seen from the above that in the electronic device provided by the embodiment of the present invention, through the configuration items of each server process stored in the distributed application coordination process, each service process can directly obtain the required configuration items from the distributed application coordination process. There is no need to store corresponding configuration files for each service process, thereby reducing the number of configuration files stored in the distributed system, thereby reducing resource waste in the distributed system.

In yet another embodiment provided by the present invention, a computer-readable storage medium is also provided. The computer-readable storage medium stores instructions that, when run on a computer, cause the computer to execute any one of the above embodiments. The service process starting method.

In yet another embodiment provided by the present invention, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute the service process starting method described in any of the above embodiments.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, e.g., the computer instructions may be transferred from a website, computer, server, or data center Transmission to another website, computer, server or data center by wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains one or more available media integrated. The available media may be magnetic media (eg, floppy disk, hard disk, magnetic tape), optical media (eg, DVD), or semiconductor media (eg, Solid State Disk (SSD)), etc.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations are mutually exclusive. any such actual relationship or sequence exists between them. Furthermore, the terms "comprises," "comprises," or any other variations thereof are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also those not expressly listed other elements, or elements inherent to the process, method, article or equipment. Without further limitation, an element defined by the statement "comprises a..." does not exclude the presence of additional identical elements in a process, method, article, or apparatus that includes the stated element.

Each embodiment in this specification is described in a related manner. The same and similar parts between the various embodiments can be referred to each other. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiment, electronic equipment embodiment, storage medium embodiment and computer program product embodiment, since they are basically similar to the method embodiment, the description is relatively simple. For relevant details, please refer to the partial description of the method embodiment. That’s it.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (10)

1. A method for starting a service process, characterized in that it is applied to a distributed application coordination process of a node in a distributed system. The node includes a distributed application coordination process and at least one service process. The distributed application coordination process is The application coordination process stores information about the configuration items of each service process. The method includes: Receive a first query request. The first query request is the request information used to obtain the configuration items of any of the service processes when they are started. The configuration items include at least one of the following: number of threads, cache size, port number, and The maximum length of the queue; According to the first query request, query the information of the configuration item corresponding to the first query request from the stored configuration item information; The queried information about the configuration item corresponding to the first query request is sent to the service process, so that the service process is started according to the information about the configuration item corresponding to the first query request. 2. The method according to claim 1, characterized in that, the method further comprises: Receive updated information for any of the configuration items; Update the stored configuration item according to the update information; Synchronize the updated configuration item to the at least one service process. 3. The method according to claim 2, characterized in that, the method further comprises: Receive the registration information of any of the service processes; Synchronizing the updated configuration items to the at least one service process includes: According to the registration information, the updated configuration item information is sent to the at least one service process, so that any of the service processes updates its configuration item based on the updated configuration item information. 4. The method of claim 2, wherein synchronizing the updated configuration items to the at least one service process includes: Receive a second query request, which is request information sent by any of the service processes according to a preset time interval for querying its configuration items; According to the second query request, query the information of the configuration item corresponding to the second query request from the stored information of the configuration item; Send the queried information on the configuration item corresponding to the second query request to the service process, so that the service process performs the configuration on the configuration item based on the information on the configuration item corresponding to the second query request. renew. 5. A service process starting device, characterized in that it is applied to a distributed application coordination process of a node in a distributed system. The node includes a distributed application coordination process and at least one service process. The distributed application coordination process is The application coordination process stores information about the configuration items of each service process. The device includes: A receiving module, configured to receive a first query request. The first query request is the request information used to obtain the configuration items of any service process when it is started. The configuration items include at least one of the following: number of threads, cache size, Port number and maximum queue length; A query module, configured to query the information of the configuration item corresponding to the first query request from the stored information of the configuration item according to the first query request; A sending module, configured to send the queried information about the configuration item corresponding to the first query request to the service process, so that the service process is started according to the information about the configuration item corresponding to the first query request. 6. The device according to claim 5, characterized in that the device further comprises: An update module, configured to receive update information for any of the configuration items; update the stored configuration item according to the update information; and synchronize the updated configuration item to the at least one service process. 7. The device according to claim 6, characterized in that: The receiving module is also used to receive the registration information of any of the service processes; The update module is also configured to send updated configuration item information to the at least one service process according to the registration information, so that the at least one service process can, according to the updated configuration item information, Update its configuration items. 8. The device according to claim 6, characterized in that the update module is also used to: Receive a second query request, which is request information sent by any of the service processes according to a preset time interval for querying its configuration items; According to the second query request, query the information of the configuration item corresponding to the second query request from the stored information of the configuration item; Send the queried information on the configuration item corresponding to the second query request to the service process, so that the service process performs the configuration on the configuration item based on the information on the configuration item corresponding to the second query request. renew. 9. An electronic device, characterized in that it includes a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory complete communication with each other through the communication bus; Memory, used to store computer programs; The processor is used to implement the method steps described in any one of claims 1-4 when executing a program stored in the memory. 10. A computer-readable storage medium, characterized in that a computer program is stored in the computer-readable storage medium, and when the computer program is executed by a processor, the method steps of any one of claims 1-4 are implemented.