Skip to main content
Version: 19

Description of log files

4D applications can generate several log files that are useful for debugging or optimizing their execution. Logs are usually started or stopped using selectors of the SET DATABASE PARAMETER or WEB SET OPTION commands and are stored in the Logs folder of the project.

Information logged needs to be analyzed to detect and fix issues. This section provides a comprehensive description of the following log files:

Note: When a log file can be generated either on 4D Server or on the remote client, the word "Server" is added to the server-side log file name, for example "4DRequestsLogServer.txt"

Log files share some fields so that you can establish a chronology and make connections between entries while debugging:

  • sequence_number: this number is unique over all debug logs and is incremented for each new entry whatever the log file, so that you can know the exact sequence of the operations.
  • connection_uuid: for any 4D process created on a 4D client that connects to a server, this connection UUID is logged on both server and client side. It allows you to easily identify the remote client that launched each process.

4DRequestsLog.txt

This log file records standard requests carried out by the 4D Server machine or the 4D remote machine that executed the command (excluding Web requests).

How to start this log:

  • on the server:
SET DATABASE PARAMETER(4D Server log recording;1)
//server side
  • on a client:
SET DATABASE PARAMETER(Client Log Recording;1)
//remote side

This statement also starts the 4DRequestsLog_ProcessInfo.txt log file.

Headers

This file starts with the following headers:

  • Log Session Identifier
  • Hostname of the server that hosts the application
  • User Login Name: login on the OS of the user that ran the 4D application on the server.

Contents

For each request, the following fields are logged:

Field nameDescription
sequence_numberUnique and sequential operation number in the logging session
timeDate and time using ISO 8601 format: 'YYYY-MM-DDTHH:MM:SS.mmm'
systemidSystem ID
componentComponent signature (e.g., '4SQLS' or 'dbmg')
process_info_index Corresponds to the "index" field in 4DRequestsLog_ProcessInfo.txt log, and permits linking a request to a process.
requestRequest ID in C/S or message string for SQL requests or LOG EVENT messages
bytes_inNumber of bytes received
bytes_outNumber of bytes sent
server_duration | exec_durationDepends on where the log is generated:
  • server_duration when generated on the client --Time taken in microseconds for the server to process the request and return a response. B to F in image below, OR
  • exec_duration when generated on the server --Time taken in microseconds for the server to process the request. B to E in image below.
  • write_durationTime taken in microseconds for sending the:
  • Request (when run on the client). A to B in image below.
  • Response (when run on the server). E to F in image below.
  • task_kindPreemptive or cooperative (respectively 'p' or 'c')
    rttTime estimate in microseconds for the client to send the request and the server to acknowledge it. A to D and E to H in image below.
  • Only measured when using the ServerNet network layer, returns 0 when used with the legacy network layer.
  • For Windows versions prior to Windows 10 or Windows Server 2016, the call will return 0.
  • Request flow:

    4DRequestsLog_ProcessInfo.txt

    This log file records information on each process created on the 4D Server machine or the 4D remote machine that executed the command (excluding Web requests).

    How to start this log:

    • on the server:
    SET DATABASE PARAMETER(4D Server log recording;1) //server side
    • on a client:
    SET DATABASE PARAMETER(Client Log Recording;1) //remote side

    This statement also starts the 4DRequestsLog.txt log file.

    Headers

    This file starts with the following headers:

    • Log Session Identifier
    • Hostname of the server that hosts the application
    • User Login Name: login on the OS of the user that ran the 4D application on the server.

    Contents

    For each process, the following fields are logged:

    Field nameDescription
    sequence_numberUnique and sequential operation number in the logging session
    timeDate and time using ISO 8601 format: "YYYY-MM-DDTHH:MM:SS.mmm"
    process_info_indexUnique and sequential process number
    CDB4DBaseContextDB4D component database context UUID
    systemidSystem ID
    server_process_idProcess ID on Server
    remote_process_idProcess ID on Client
    process_nameProcess name
    cIDIdentifier of 4D Connection
    uIDIdentifier of 4D Client
    IP ClientIPv4/IPv6 address
    host_nameClient hostname
    user_nameUser Login Name on client
    connection_uuidUUID identifier of process connection
    server_process_unique_idUnique process ID on Server

    HTTPDebugLog.txt

    This log file records each HTTP request and each response in raw mode. Whole requests, including headers, are logged; optionally, body parts can be logged as well.

    How to start this log:

    WEB SET OPTION(Web debug log;wdl enable without body)  
    //other values are available

    The following fields are logged for both Request and Response:

    Field nameDescription
    SocketIDID of socket used for communication
    PeerIPIPv4 address of host (client)
    PeerPortPort used by host (client)
    TimeStampTimestamp in milliseconds (since system startup)
    ConnectionIDConnection UUID (UUID of VTCPSocket used for communication)
    SequenceNumberUnique and sequential operation number in the logging session

    4DDebugLog.txt (standard)

    This log file records each event occurring at the 4D programming level. Standard mode provides a basic view of events.

    How to start this log:

    SET DATABASE PARAMETER(Debug Log Recording;2)  
    //standard, all processes

    SET DATABASE PARAMETER(Current process debug log recording;2)
    //standard, current process only

    The following fields are logged for each event:

    Column #Description
    1Unique and sequential operation number in the logging session
    2Date and time in ISO 8601 format (YYYY-MM-DDThh:mm:ss.mmm)
    3Process ID (p=xx) and unique process ID (puid=xx)
    4Stack level
    5Can be Command Name/ Method Name/Message/ Task Start Stop info/Plugin Name, event or Callback/Connection UUID
    6Time taken for logging operation in milliseconds

    4DDebugLog.txt (tabular)

    This log file records each event occurring at the 4D programming level in a tabbed, compact format that includes additional information (compared to the standard format).

    How to start this log:

    SET DATABASE PARAMETER(Debug Log Recording;2+4)  
    //extended tabbed format, all processes

    SET DATABASE PARAMETER(Current process debug log recording;2+4)
    //extended, current process only

    The following fields are logged for each event:

    Column #Field nameDescription
    1sequence_numberUnique and sequential operation number in the logging session
    2timeDate and time in ISO 8601 format (YYYY-MM-DDThh:mm:ss.mmm)
    3ProcessIDProcess ID
    4unique_processIDUnique process ID
    5stack_levelStack level
    6operation_typeLog operation type. This value may be an absolute value:
    1. Command
    2. Method (project method, database method, etc.)
    3. Message (sent by LOG EVENT command only)
    4. PluginMessage
    5. PluginEvent
    6. PluginCommand
    7. PluginCallback
    8. Task
    9. Member method (method attached to a collection or an object)
    When closing a stack level, the operation_type, operation and operation_parameters columns have the same value as the opening stack level logged in the stack_opening_sequence_number column. For example:
    1. 121 15:16:50:777 5 8 1 2 CallMethod Parameters 0
    2. 122 15:16:50:777 5 8 2 1 283 0
    3. 123 15:16:50:777 5 8 2 1 283 0 122 3
    4. 124 15:16:50:777 5 8 1 2 CallMethod Parameters 0 121 61
    The 1st and 2nd lines open a stack level, the 3rd and 4th lines close a stack level. Values in the columns 6, 7 and 8 are repeated in the closing stack level line. The column 10 contains the stack level opening sequence numbers, i.e. 122 for the 3rd line and 121 for the 4th.
    7operationMay represent (depending on operation type):
  • a Language Command ID (when type=1)
  • a Method Name (when type=2)
  • a combination of pluginIndex;pluginCommand (when type=4, 5, 6 or 7). May contain something like '3;2'
  • a Task Connection UUID (when type=8)
  • 8operation_parametersParameters passed to commands, methods, or plugins
    9form_eventForm event if any; empty in other cases (suppose that column is used when code is executed in a form method or object method)
    10stack_opening_sequence_numberOnly for the closing stack levels: Sequence number of the corresponding opening stack level
    11stack_level_execution_timeOnly for the closing stack levels: Elapsed time in micro seconds of the current logged action; only for the closing stack levels (see 10th columns in lines 123 and 124 in the log above)

    4DDiagnosticLog.txt

    This log file records many events related to the internal application operation and is human-readable. You can include custom information in this file using the LOG EVENT command.

    How to start this log:

     SET DATABASE PARAMETER(Diagnostic log recording;1) //start recording

    The following fields are logged for each event:

    Field NameDescription
    sequenceNumberUnique and sequential operation number in the logging session
    timestampDate and time in ISO 8601 format (YYYY-MM-DDThh:mm:ss.mmm)
    loggerIDOptional
    componentSignatureOptional - internal component signature
    messageLevelInfo, Warning, Error
    messageDescription of the log entry

    Depending on the event, various other fields can also be logged, such as task, socket, etc.

    4DSMTPLog.txt, 4DPOP3Log.txt, and 4DIMAPLog.txt

    These log files record each exchange between the 4D application and the mail server (SMTP, POP3, IMAP) that has been initiated by the following commands:

    The log files can be produced in two versions:

    • a regular version:

      • named 4DSMTPLog.txt, 4DPOP3Log.txt, or 4DIMAPLog.txt
      • no attachments
      • uses an automatic circular file recycling each 10 MB
      • intended for usual debugging

      To start this log:

      SET DATABASE PARAMETER(SMTP Log;1) //start SMTP log 
      SET DATABASE PARAMETER(POP3 Log;1) //start POP3 log
      SET DATABASE PARAMETER(IMAP Log;1) //start IMAP log

      4D Server: Click on the Start Request and Debug Logs button in the Maintenance Page of the 4D Server administration window.

      This log path is returned by the Get 4D file command.

    • an extended version:

      • attachment(s) included no automatic recycling

      • custom name

      • reserved for specific purposes

        To start this log:

        $server:=New object
        ...
        //SMTP
        $server.logFile:="MySMTPAuthLog.txt"
        $transporter:=SMTP New transporter($server)

        // POP3
        $server.logFile:="MyPOP3AuthLog.txt"
        $transporter:=POP3 New transporter($server)

        //IMAP
        $server.logFile:="MyIMAPAuthLog.txt"
        $transporter:=IMAP New transporter($server)

    Contents

    For each request, the following fields are logged:

    Column #Description
    1Unique and sequential operation number in the logging session
    2Date and time in RFC3339 format (yyyy-mm-ddThh:mm:ss.ms)
    34D Process ID
    4Unique process ID
    5
    • SMTP,POP3, or IMAP session startup information, including server host name, TCP port number used to connect to SMTP,POP3, or IMAP server and TLS status,or
    • data exchanged between server and client, starting with "S <" (data received from the SMTP,POP3, or IMAP server) or "C >" (data sent by the SMTP,POP3, or IMAP client): authentication mode list sent by the server and selected authentication mode, any error reported by the SMTP,POP3, or IMAP Server, header information of sent mail (standard version only) and if the mail is saved on the server,or
    • SMTP,POP3, or IMAP session closing information.

    ORDA client requests

    This log records each ORDA request sent from a remote machine. You can direct log information to memory or to a file on disk. The name and location of this log file are your choice.

    How to start this log:

    //to be executed on a remote machine
    ds.startRequestLog(File("/PACKAGE/Logs/ordaLog.txt"))
    //can be also sent to memory

    If you want to use the unique sequence number in ORDA request log, you need to trigger it:

    //to be executed on a remote machine

    SET DATABASE PARAMETER(Client Log Recording;1)
    //to enable log sequence number

    ds.startRequestLog(File("/PACKAGE/Logs/ordaLog.txt"))
    //can be also sent to memory

    SET DATABASE PARAMETER(Client Log Recording;0)
    //disabling sequence number

    The following fields are logged for each request:

    Field nameDescriptionExample
    sequenceNumberUnique and sequential operation number in the logging session104
    urlClient ORDA request URL"rest/Persons(30001)"
    startTimeStarting date and time using ISO 8601 format"2019-05-28T08:25:12.346Z"
    endTimeEnding date and time using ISO 8601 format"2019-05-28T08:25:12.371Z"
    durationClient processing duration (ms)25
    responseServer response object{"status":200,"body":{"__entityModel":"Persons",[...]