# Logs -------------------------------------------------------------------------------- title: "Introduction" description: "Catalyst provides detailed logs of all function executions in your application or microservice that enables you to gain insights on failures, exceptions, or timeouts." last_updated: "2026-03-18T07:41:08.553Z" source: "https://docs.catalyst.zoho.com/en/devops/help/logs/introduction/" service: "DevOps" -------------------------------------------------------------------------------- # Logs ## Introduction Catalyst Logs is a Catalyst DevOps component that displays the logs of all {{%link href="/en/serverless/help/functions/introduction" %}}Catalyst function{{%/link%}} executions. You can view the logs to check for errors in function executions, along with other necessary execution information of the execution. Logs enable you to access the records of all successful and failed function executions instantly after they are executed, including the functions that were executed internally. This helps you identify bugs in your code easily and resolve problem areas during the testing phase of your Catalyst application. Catalyst offers native support for logging function executions of both Java, Node.js and Python platforms. Logs display the execution history of {{%link href="/en/serverless/help/functions/basic-io" %}}all six types of Catalyst functions{{%/link%}} : Basic I/O, Advanced I/O, Event, Cron, Integration and Browser Logic functions. You can manually push specific events or data to logs while writing a Catalyst function of any function type or for any platform. You can do this to push exceptions and errors that you anticipate in the function's execution. This is usually done by including a single statement in the function definition. You can also define the severity level of each error that is pushed to the logs. Catalyst Logs are fundamentally of two types: * {{%bold%}}Access Logs:{{%/bold%}} These contain the log details of an external access layer of a function's execution. The functions that are usually invoked manually by the users are logged in this layer. This type is applicable only for Basic I/O, Advanced I/O, Integration and Browser Logic Catalyst functions. * {{%bold%}}Application Logs:{{%/bold%}} These contain the log details of an internal application layer of a function's execution. These include the functions that are invoked manually by the users, or executed internally by the application. This log type is applicable for all types of Catalyst functions. Catalyst retains the logs of function executions for seven days in the {{%link href="/en/deployment-and-billing/environments/development-environment/" %}}Development environment{{%/link%}}, and fourteen days in the {{%link href="/en/deployment-and-billing/environments/production-environment" %}}Production environment{{%/link%}}. You will be able to access the logs of all executions in these time periods in the Development and Production environments respectively. {{%note%}}{{%bold%}}Note:{{%/bold%}} While Catalyst Logs provide basic information about your function executions, {{%link href="/en/devops/help/apm/introduction" %}}Application Performance Monitoring{{%/link%}} is an enhancement to Catalyst Logs which provides in-depth detailed insights of the function executions and enables you to monitor your functions in a better way. You can enable APM for your project and access detailed performance reports and statistics of your functions.{{%/note%}} You can learn more about the other components of the DevOps service from {{%link href="/en/devops" %}}this page{{%/link%}}. -------------------------------------------------------------------------------- title: "Pushing to Logs" description: "Catalyst provides detailed logs of all function executions in your application or microservice that enables you to gain insights on failures, exceptions, or timeouts." last_updated: "2026-03-18T07:41:08.553Z" source: "https://docs.catalyst.zoho.com/en/devops/help/logs/pushing-to-logs/" service: "DevOps" -------------------------------------------------------------------------------- ## Pushing to Logs You can push events and data to logs while writing a Catalyst function by including a statement in the function definition. This statement differs based on the function stack and the function type. Catalyst enables you to write upto 1500 characters to the logs. You can therefore pass data in this range and include messages that require to be pushed. You can also include the log level of a function statement to indicate its severity. The {{%bold%}}log levels{{%/bold%}} are only relevant to Application logs and will not be displayed in Access logs. The log levels differ for **Java**, **Node.js** and **Python** functions. Refer to the {{%link href="/en/devops/help/logs/application-logs" %}}Application Logs{{%/link%}} section to view the different log levelssupported by all platforms. The methods to include in your function code to push the response data of each function stack and type are mentioned below: #### Java Functions You must include the following method in your function definition to push to logs for {{%bold%}}all function types{{%/bold%}}: {{%code class="language-java"%}}LOGGER.log(){{%/code%}} You can include the log level for a Java function along with this statement. For example, to push a certain response obtained to the {{%badge%}}INFO{{%/badge%}} level in a Java function, you can write: {{%code class="language-java"%}}LOGGER.log(Level.INFO, "Hello "+name);{{%/code%}} Alternatively you can also use {{%badge%}}logger.severe(){{%/badge%}}, {{%badge%}}logger.warning(){{%/badge%}} or {{%badge%}}logger.info(){{%/badge%}} for all function types. #### Node.js Functions The Basic I/O functions support a different method to write data to Logs from the other function types in the Node.js platform. You must include the following method in your function definition to push to logs in a {{%bold%}}Basic I/O function{{%/bold%}}: {{%code class="language-javascript"%}}context.log(){{%/code%}} For example, to push a certain response obtained to logs, you can write: {{%code class="language-javascript"%}}context.log("Value : " + result);{{%/code%}} Similar to Java functions, you can include the log level supported by Node.js functions along with this statement. For functions of the {{%bold%}}other types{{%/bold%}} (Advanced I/O, Cron, Event, Integration and Browser Logic functions), you must include the method below in your function definition to push to logs. This method applies to Basic I/O function as well. {{%code class="language-javascript"%}}console.log(){{%/code%}} This is a {{%link href="https://nodejs.org/api/console.html#console_console_log_data_args" %}}native Node.js method{{%/link%}} to write to logs that is supported by Catalyst. The following example contains a push to logs statement of the ERROR log level in a catch block: {{%code class="language-javascript"%}}catch (err) { console.error(err); res.status(500).send({ message: 'Internal Server Error. Please try again after sometime.', error: err }) }{{%/code%}} Similarly, you can also other direct methods like {{%badge%}}console.warning(){{%/badge%}}, {{%badge%}}console.info(){{%/badge%}} or {{%badge%}}console.debug(){{%/badge%}} to push the logs for all function types. #### Python Functions The Basic I/O functions support a different method to write data to Logs from the other function types in the Python platform. You must include the following method in your function definition to push to logs in a {{%bold%}}Basic I/O function{{%/bold%}}: {{%code class="language-javascript"%}}context.log(){{%/code%}} Similar to Node.js functions, you can write relevant informative messages and push them as a response to the logs. For functions of the {{%bold%}}other types{{%/bold%}} (Advanced I/O, Cron, Event, Integration and Browser Logic functions), you must include the method below in your function definition to push to logs: {{%code class="language-javascript"%}}LOGGER.log(Level.INFO, "Hello "+name);{{%/code%}} Alternatively you can also use direct methods like {{%badge%}}logger.critical(){{%/badge%}}, {{%badge%}}logger.warning(){{%/badge%}}, {{%badge%}}logger.error(){{%/badge%}}, {{%badge%}}logger.info(){{%/badge%}} or {{%badge%}}logger.debug(){{%/badge%}} for all function types. {{%note%}}{{%bold%}}Note:{{%/bold%}} Refer to the {{%link href="/en/devops/help/logs/application-logs" %}}Application Logs{{%/link%}} section to view the log levels supported by Java, Node.js and Python functions.{{%/note%}} -------------------------------------------------------------------------------- title: "Access Logs" description: "Catalyst provides detailed logs of all function executions in your application or microservice that enables you to gain insights on failures, exceptions, or timeouts." last_updated: "2026-03-18T07:41:08.554Z" source: "https://docs.catalyst.zoho.com/en/devops/help/logs/access-logs/" service: "DevOps" -------------------------------------------------------------------------------- # Access Logs Access logs include the log details of an external access layer of a function's execution. Consider a gateway with two layers that need to be passed, to access and execute a Catalyst function. Access logs show relevant details of the function's invocation and execution about the external access layer in this gateway. These details include the User ID of the user invoking the function, the HTTP request method used to invoke the function, and more. The details of the response in this external layer are also shown in these logs, such as the response status, response time, etc. The functions that can be manually invoked by a user are the ones that pass through this external access layer. This includes only {{%bold%}} Basic I/O, Advanced I/O, Integration and Browser Logic function{{%/bold%}} executions in your application, as they can be invoked manually by the users. Integration functions are not invoked through a Function URL like Basic or Advanced I/O functions, but they are still accessed through external means by the users that call upon the integration service. Therefore, these function types are included in Access logs. Event and Cron functions cannot be accessed through an endpoint and do not pass through this layer. They directly pass through the Application layer. Therefore, Event and Cron function executions will not be included in the Access logs. They will only be included in the Application logs. To open the logs for your Catalyst project, navigate to the {{%bold%}}_Host and Manag_{{%/bold%}}e section in the Catalyst console, then click {{%bold%}}Logs{{%/bold%}}. <br /> {{%note%}}{{%bold%}}Note:{{%/bold%}} You can either view Access logs or Application logs. You will not be able to view the combined results of both log types. You must select the log type from the dropdown in the {{%italics%}}Filters{{%/italics%}} section.{{%/note%}} ### Access Log Filters The Access logs and Application logs contain different sets of filters that you can use to filter the log data that are displayed. The filters available for Access logs are shown below. * {{%bold%}}Log Type:{{%/bold%}} You must select {{%bold%}}Access{{%/bold%}} or {{%bold%}}Application{{%/bold%}} log type to view the respective logs. The other filters will change slightly based on the type you select. * {{%bold%}}Date/Time/Time zone:{{%/bold%}} You can select a time period of logs to show from the variety of options in the Date/Time dropdown list. <br /> <br /> You can also select a custom time range from a calendar, by clicking on the dates that you require and entering the time. Click {{%bold%}}Apply{{%/bold%}} after the selection. You can select a preferred time zone by clicking the dropdown. Click **Apply** after the selection. {{%note%}}{{%bold%}}Note:{{%/bold%}} You can change the default timezone of your Catalyst project in the {{%link href="/en/getting-started/set-up-a-catalyst-project/general-settings/"%}}General Settings{{%/link%}}. However if you wish to switch the timezone for viewing function logs here, you can use the filter specified above.{{%/note%}} * {{%bold%}}Function:{{%/bold%}} You must select one or more functions from this dropdown list to view their logs. The Access logs only list Basic I/O, Advanced I/O, Integration, and Browser Logic functions.<br /> * {{%bold%}}Keyword:{{%/bold%}} You can also search for a specific keyword that you might have included in your log message while writing the function, to view logs that include this keyword. <br /> <br /> For example, to access the execution logs of a function that contains a specific path in its request URL, you can enter that path as the keyword and search for the logs. Click {{%bold%}}Search{{%/bold%}} after you set the filters. ### Access Log Results The results of Access logs will contain information relating to the external access layer such as the function name, User ID of the user who invoked it, the invocation URL, time of execution, request method, the host address, and response details such as the HTTP response status and response time. The logs are generally indexed instantly, but there could be a 5 minute delay in indexing in some cases. When the filter section is hidden, the results page shows a {{%bold%}}Refresh Logs{{%/bold%}} button. You can click this to obtain the latest log results. -------------------------------------------------------------------------------- title: "Application Logs" description: "Catalyst provides detailed logs of all function executions in your application or microservice that enables you to gain insights on failures, exceptions, or timeouts." last_updated: "2026-03-18T07:41:08.554Z" source: "https://docs.catalyst.zoho.com/en/devops/help/logs/application-logs/" service: "DevOps" -------------------------------------------------------------------------------- # Application Logs Application logs display the log details of the internal application layer in the gateway of a function's execution. The internal layer of the gateway, as explained in the {{%link href="/en/devops/help/logs/access-logs" %}}Access Logs section{{%/link%}}, logs application-level details. This includes details related to the processing of the function, such as the messages passed to the logs at particular instances, log severity levels, etc. This internal application-level logging applies to both functions that were invoked manually by a user or executed internally by the application. An example of an internal function execution is, a daily Cron execution that triggers the invocation of a Cron function automatically everyday. Log details of such functions are also included in the Application logs. Application logs therefore contain execution logs of {{%bold%}}all function types{{%/bold%}}, including Event and Cron functions. <br> ### Log Levels of Java, Node.js and Python Functions Application logs include log levels that indicate the severity of an error event in a function execution. As mentioned in the {{%link href="/en/devops/help/logs/pushing-to-logs" %}}Pushing to Logs section{{%/link%}}, you can assign an appropriate log level to an event or an error when you code the function. The log levels differ based on the function stack, i.e., Java, Node.js or Python functions. The log levels of {{%bold%}}Java platform{{%/bold%}} supported by Catalyst that you can use in your functions are: * {{%bold%}}Severe{{%/bold%}}: Indicates a serious failure * {{%bold%}}Warning:{{%/bold%}} Indicates a potential problem * {{%bold%}}Info:{{%/bold%}} Indicates an informational message The log levels that you can use in Node.js functions are: * {{%bold%}}Error:{{%/bold%}} Indicates an unexpected error * {{%bold%}}Info:{{%/bold%}} Indicates an informational message * {{%bold%}}Warning:{{%/bold%}} Indicates a potential problem * {{%bold%}}Debug:{{%/bold%}} Indicates information about troubleshooting and testing the application The log levels of Python platform supported by Catalyst include: * {{%bold%}}Critical:{{%/bold%}} Indicates an event that can be recovered from. * {{%bold%}}Error:{{%/bold%}} Indicates an unexpected error * {{%bold%}}Warning:{{%/bold%}} Indicates a potential problem * {{%bold%}}Info:{{%/bold%}} Indicates an informational message * {{%bold%}}Debug:{{%/bold%}} Indicates information about troubleshooting and testing the application. You can use select one of these log levels in the filters to fetch execution results of that level alone. <br> ### Application Log Filters Application logs include some more filters in addition to the Access log filters. The filters available for Application logs are shown below. <br /> The Log Type, Date/Time/Time Zone, and Keyword filters are the same as the {{%link href="/en/devops/help/logs/access-logs/#access-log-filters" %}}Access log filters{{%/link%}}. * {{%bold%}}Function:{{%/bold%}} The Function filter in Application logs lists functions of all types. You must select one or more functions from this dropdown list to view their logs. * {{%bold%}}Log Level:{{%/bold%}} Log Level: Based on the functions that you select, the log levels of Java or Node.js functions are shown. If you select functions of both Java and Node.js in the Function dropdown, a mixture of both Java and Node.js log levels will be available in this dropdown. Relevant details of each function will be shown in the results. * {{%bold%}}Execution ID:{{%/bold%}} When a Cron or an Event function executes, a unique Execution ID is associated with each execution. You can filter the logs by providing this Execution ID, and fetch that particular execution alone. <br /> The execution history section of an {{%link href="/en/cloud-scale/help/event-listeners/introduction" %}}Event Listener{{%/link%}} or a {{%link href="/en/cloud-scale/help/cron/introduction" %}}Cron{{%/link%}} also contains a direct access to Logs. You can select a particular execution, and click on the {{%bold%}}View Logs{{%/bold%}} button to open Logs from there. Click {{%bold%}}Search{{%/bold%}} after you set the filters. <br> ### Application Log Results The results of Application logs will contain information relating to the internal application layer, such as the function name, time of execution, log level, and the messages pushed by the developers when specific events occur. When the filter section is hidden, the results page shows a {{%bold%}}Refresh Logs{{%/bold%}} button. You can click this to obtain the latest log results. -------------------------------------------------------------------------------- title: "Managing Alerts in Logs" description: "Catalyst provides detailed logs of all function executions in your application or microservice that enables you to gain insights on failures, exceptions, or timeouts." last_updated: "2026-03-18T07:41:08.554Z" source: "https://docs.catalyst.zoho.com/en/devops/help/logs/managing-alerts/" service: "DevOps" -------------------------------------------------------------------------------- # Managing Alerts in Logs As mentioned {{%link href="/en/devops/help/logs/introduction" %}}earlier{{%/link%}}, you can create application alerts for logs directly from the Logs section without having to navigate to that component. {{%link href="/en/devops/help/application-alerts/implementation/#create-an-alert" %}}Application alerts enable you to configure{{%/link%}} automated log searches to be executed in a recurring schedule, by specifying the search query and the frequency of execution. Catalyst will send automated emails with the results of the log search each time. You can configure alerts by clicking the **Manage Alerts** option available in the top right-hand side of the console. Catalyst will open a pop-up to configure the alert. You must enter the alert name and details, such as the type of log, the criteria to trigger the alert, the frequency, and the email address to notify. You can learn more about these from the {{%link href="/en/devops/help/application-alerts/introduction" %}}Application Alerts help page{{%/link%}}. Click **Confirm** after you configure the alert. Catalyst will now send emails whenever alerts are triggered for these specifications.