Introduction
This article describes how to configure a new synchronization among r_keeper_7 databases.
The minimal r_keeper_7 version required for synchronization is 7.6.4.
Synchronization Description
Interaction Procedure
To enable synchronization, indicate the setting below in the ini file of the server.
[DBSYNC]
UseDBSync=1
When run in this mode, the directory server will create (next to the database file rk7.udb) the file called rk7.udb.SQLite and a folder where it will store backup copies, log files and the filtering settings file for transferring them to client applications.
By default, this is the folder DBSync\outgoing in the folder containing the database.
Transfer to client applications is performed over the network. Network access to this folder is enabled by the WebDAV protocol. To work with WebDAV, every server runs the nginx that is automatically accessed through the HTTP interface of the server. If ini files of client applications do not have a static ReqSourceURL, client applications individually request the host and port from the server by default when connecting to it using the network name.
Below is the module interaction procedure in synchronization 2.0:
Synchronization Settings
Open the directory server settings file (rk7srv.INI) and add the setting UseDBSync=1 to the [DBSYNC] section. There is no default section so it should also be specified.
;;first line comment to avoid problems with BOM
[REFSERVER] Server = RK7TEST
UDBFILE = ..\..\base\rk7.udb
MainLang = .\localize\rkeeper7\rkeeper7.ru.xlf
AltLang = .\localize\rkeeper7\rkeeper7.en.xlf
WorkModules = ..\..\base\workmods
ErrorLogSize = 10485760
DisableSMARTVerify = 1
UseNetChecking=1
LicServerIP=l.ucs.ru:60606
Usesql=1
[DBSYNC]
UseDBSync=1
[NETKERN]
Protocols = tcpsoc.DLL
Save the file and run the directory server.
The DBSync folder containing the outgoing folder will appear in the folder RK7\base\. In the outgoing the server will store backup copies and log files for transferring them to client applications.
Indicate the same setting in other applications: report server, POS server and POS stations.
[DBSYNC]
UseDBSync=1
Save the settings files and run the applications.
To check synchronization, you can open a folder in a browser. To do so, open the link of the following format:
https://
http_host
:
http_port
/rk7api/v1/dbsync/
As an example, open the link https://127.0.0.1:54318/rk7api/v1/dbsync/ (this is my directory server). The authentication window will appear.
Enter the user name in Latin characters with the HTTP_Access right and the password.
Click Sign in. You will see the list of files in the folder:
If the list has appeared, synchronization is enabled. You can perform an additional synchronization check by changing the name of a dish on the menu and checking it at the POS station.
You can check the POS server and report server in the same way.
Description of INI Files
Directory Server
The settings file for the report server is rk7srv.INI
[DBSync] ; Enabling the second database SQLiteCMN for the general (main) directory database and the local directory database,
; and recording of their log files and backups for synchronization by databases to function.
; When run in this mode, the directory server will create (next to the database file rk7.udb) the file called rk7.udb.SQLite
; and a folder where it will store backup copies, log files and the filtering settings file
; for transferring them to client applications. See more details below, in the description of the OutputPath parameter.
; By default, this is the folder DBSync\outgoing in the folder containing the database.
; Network access to this folder is automatically enabled by the WebDAV protocol.
; To that end every server runs its own nginx that is automatically accessed
; through the HTTP interface of the server. If ini files of client applications do not have a static ReqSourceURL (see below),
client applications individually request the host and port from the server by default when connecting to it using the network name.
; To perform checks, you can establish a connection to this folder, for example through a web browser, using the URL of the format https://<http host>:<http port>/rk7api/v1/dbsync/ UseDBSync = 1
; The folder that will contain created backup files, log files and the filtering settings file.
; You can do without indicating it as the default folder is DBSync\outgoing\ next to the directory database file
; of the directory server. Client applications take files from it for updating their databases.
; They access it either through the embedded WebDAV or directly as a folder in the file system or in any other way.
; OutputPath = <DataBasePath>DBSync\outgoing
; How many transactions are required for a backup. By default, every 1000 log files are backed up.
; BackupOnVersionsDelta = 2000
; What total log size (a percentage of the last backup size) is required to make a new backup.
; By default, this is 30%: a new backup is made once the total size of log files
; created since the last backup reaches 30% of the size of the last backup.
; BackupOnJournalSizeMultiplier = 30
; What total size of log files should be reached so that the earliest of them are deleted from the OutputPath.
; Indicated as a percentage of the last backup size; by default, this is 300.
; That is, the default size of stored log files equals three sizes of the database.
; BackupMaxTotalSizeMultiplier = 300
; Minimal log file storage time in hours
; By default, logs are stored for no less than 8 hours
; MinSaveJournalHours = 8
; What number of backups should be reached so that the earliest of them are deleted from the OutputPath.
; By default, two backups are stored: the last one and the next-to-last one (as a safeguard)
; BackupCountLimit = 2
; To protect file exchange through http, you can set a system password; a parameter value must start with ":"
; ServerLoginInfo = :<Password>
; Enabling the nginx debugging mode. 1 means 'enabled'. The default value is 0.
; NginxDebug = 0
Report server
The report server settings file is repserv.ini
[DBSYNC]
; Allowing to receive backups, logs and the filtering settings file from the upstream server for synchronizing
; the main directory database with it and enabling the second database SQLiteCMN for local directories
; and for recording its log files and backups for synchronization by databases to function.
; When run in this mode, the report server will create (next to the database file rk7.udb) the folder called rk7.udb.SQLiteDBSync\outgoing
; where it will store backups, log files and the filtering settings file for transferring them to its client
; applications both through the main directory database that are received from the upstream server and applied to its database
; and through the local database that are generated when editing local directories on this server. UseDBSync = 1
; As for the outgoing folder settings, see the description of the similar section dealing with the directory server parameters.
; Access to the OutputPath folder on the upstream server can be granted via the WebDAV protocol and via external means;
; in this case, in the ReqSourceURL parameter, please indicate the URL from where to request data (Request).
; ReqSourceURL = http://<serverIP>:<WebDAVPort>/rk7api/v1/dbsync
; If this parameter has an empty value, downloading via the WebDAV protocol will be disabled.
; This is useful if the upstream server is located on the same computer or in the local network and if it is possible
; to grant access to its outgoing folder directly through the file system means.
; ReqSourceURL =
; To balance the network and server load, you can specify how many seconds should pass for processes of downloading via WebDAV
; between requests to the server about new log files or new backups. The default interval is 2 seconds.
; ReqInterval = 2
; To balance the network and server load, during downloading via WebDAV you can adjust
; the percentage of backup size that log files can take up so that when the client starts working, this backup will be downloaded
; instead of downloading and rolling those log files.
; The default value is 100 percent; if the size of required log files is larger than the backup, the backup is downloaded.
; If you indicate 200, log files must be 2 times larger than the backup for it to be downloaded,
; and if you indicate 50, the backup can be 2 times larger than logs, but it will still be downloaded.
; You should select the value of this parameter depending on the network speed, the speed at which log files are applied,
; the system slowdown when many log files are applied, etc.
; ReqStartLoadBackupMultiplier = 100
; By default, when connected via WebDAV, backups for the OutputPath folder are made locally considering the settings
; for conditions of taking backups and independently from servers. Therefore, they are made not for the same data versions for which backups
; are taken on other servers. If it is necessary to synchronize backups or to reduce some of the loads,
; there is a capability of enabling the mode in which backups are downloaded from the upstream server. It is disabled by default.
; ReqToDownloadBackups = 0
; The folder (relatively to the exe file) from where backups and log files will be taken from the closest upstream server
; for the database to be updated. By default, it is equal to <DatabasePath>DBSync\incoming
; If the ReqSourceURL parameter (see above) is not empty, it is to this folder that files will be downloaded via WebDAV.
; If the ReqSourceURL is empty, here you can specify the path to the DBSyncOutputPath folder of the upstream
; directory server or report server if it is in the same network or on the same computer; alternatively, you can specify the path to its copy received
; from the remote server via some external means.
; InputPath = <RefServerBaseFolder>\DBSync\outgoing
; The folder where processed backup and log files will be placed. Database files of local directories will also be added there.
; You can do without indicating it as the default folder is <DatabasePath>DBSync\outgoing\ next to the directory database file of the report server.
; OutputPath = <DataBasePath>DBSync\outgoing
; The mode where the report server deletes processed files from the InputPath folder after copying them to the OutputPath.
; This is useful if they are downloaded to the InputPath folder individually for a given report server.
; If the incoming folder is the outgoing folder of the upstream server and it is shared by several clients,
; this mode is inappropriate, and cleaning of this folder is monitored by the upstream server.
; Therefore, if InputPath=<DataBasePath>DBSync\incoming, by default RemoveProcessed = 1, otherwise 0.
; RemoveProcessed = 0
; To exchange files via http, you can specify a system user with a password
; For the http server:
; ServerLoginInfo = :<Password>
For the http client:
; ReqSourceLoginInfo = [<User>]:<Password>
; <User> is only for external WebDAV servers. To connect to RK7 servers, there is no need to specify the <User> (the network name will be used)!
; The same as on the directory server
; BackupOnVersionsDelta = 2000
; BackupOnJournalSizeMultiplier = 30
; BackupMaxTotalSizeMultiplier = 300
; MinSaveJournalHours = 8
; BackupCountLimit = 2
; NginxDebug = 0 [CONFIG]
; The type of the database used. The mechanism is intended to work with SQLite, so it is required to indicate SQLiteCMN or SQLiteUCS.
; Must be the same as the database type specified on the directory server.
; For now, it is impossible to specify it so there is no need to indicate it here either.
; DataBaseKind = SQLiteCMN
; Filtering settings have not changed: if required, it is enabled via SyncSchdFile.
; But when synchronization is performed by databases, filtering settings are used for reading from the database
; so they are required not only on the repeater unit but also have to be configured on each POS server and on each POS station.
; Therefore:
; When UseDBSync is enabled, servers save their filter to the OutputPath for clients to use.
; When UseDBSync is enabled and if not indicated otherwise in the SyncSchdFile parameter, clients use the filtering settings file
; from the folder specified by the InputPath parameter. It has to get there from the OutputPath of the upstream server.
; Moreover, only RestFilterIn and skipDeleteIn are used from the file specified in this parameter while the schedule is not used.
; SyncSchdFile =
POS Server
The POS server settings file is RKEEPER.INI
[DBSYNC]
; See the description of the similar section dealing with the report server parameters keeping in mind that the local directory database on the POS server is also taken solely from the upstream server.
[CONFIG]
; See the description of the similar section dealing with the report server parameters.
POS Station and Printing Station
The settings files for POS stations and printing stations are wincash.ini and winprint.ini
[DBSYNC]
; See the description of the similar section dealing with the report server parameters but parameters responsible for filling and cleaning the OutputPath folder and making backups are ignored
[CONFIG]
; The path to the folder for the database of the POS station directories.
; In the mode of synchronization by databases, a POS station also has its own database and should see where to place it.
; If not indicated, the app folder will be used.
BasePath = ..
; Instead of the DBSyncMoveToOutput parameter used on servers, the parameter is called DBSyncRemoveProcessed for POS stations
; This is the mode where the POS deletes processed files from the DBSyncInputPath folder upon processing them.
; This is useful if they are placed into the DBSyncInputPath folder individually for a given POS by some external mechanism.
; The default value is 1 if DBSyncInputPath=<DataBasePath> + 'DBSync\incoming', otherwise 0.
; DBSyncRemoveProcessed = 0
; Other than that, see the description of the similar section dealing with the POS server parameters.