############# Trace Logging ############# Overview ======== FoundationDB processes generate log files known as trace logs that include details about the sequence of events that a process performed and record a variety of metrics about that process. These log files are useful for observing the state of a cluster over time and for debugging issues that occur in the cluster, a client, or various tools. Each file contains a sequence of events for a single process, ordered by time. Clients that use the multi-version or multi-threaded client features will generate :ref:`multiple log files simultaneously `. Each entry in the log file will be either an XML event or a JSON object that containts several mandatory fields and zero or more arbitrary fields. For example, the following is an event generated in the XML format:: Most FoundationDB processes generate trace logs in the format described in this document. This includes server and client processes, fdbcli, and backup and DR tooling. Configuration ============= File Format ----------- FoundationDB trace logging * Parameters * Format Trace Files =========== * Filenames * Rolling Mandatory Fields ================ * Severity * Time * Type * Machine * LogGroup * ID Common Fields ============= * Roles Event Suppression ----------------- * SuppressedEventCount Errors ------ * Error * ErrorDescription * ErrorCode Clients ------- * Rolled Events ============= Counters ======== PeriodicEvents ============== .. mvc-logging:: Multi-Version and Multi-Threaded Client Logging ===============================================