#Deployment Logs Reference

Fetch and analyze deployment logs to debug runtime issues and monitor your deployed application.

#When to Read This Reference

Read this when:

• The user reports that their deployed application is not working correctly
• The user wants to see what errors are occurring in production
• The user needs to debug a runtime issue after deployment
• The user asks to check deployment or server logs
• The user wants to monitor application behavior after deployment

#How to Use

In the JavaScript notebook, call the fetchDeploymentLogs function:

const result = await fetchDeploymentLogs({
    afterTimestamp: (Date.now() - 3600 * 1000),  // Last hour
    message: "ERROR"
});
if (result.found) {
    console.log(result.logs);
} else {
    console.log("No deployment logs found.");
}

#Parameters

• afterTimestamp (float, optional): Only include logs after this Unix timestamp (milliseconds)
• beforeTimestamp (float, optional): Only include logs before this Unix timestamp (milliseconds)
• message (str, optional): RE2 regular expression to filter logs by message content
• messageContext (dict, optional): Context configuration for regex matches with:
  • lines (int, required): Number of lines before/after each match (0-100)
  • limit (int, required): Max matches to fetch context for (1-10)

#Return Value

Returns a dictionary with:

• logs: String containing the formatted deployment logs (empty string if none found)
• found: Boolean indicating whether any logs were found
• message: Optional message when no logs are found

#Best Practices

1. Start broad, then filter: First fetch logs without filters to understand what's available, then use message regex to narrow down
2. Use timestamps for recent issues: If the user reports a recent issue, use afterTimestamp to focus on recent logs
3. Filter by log level: Use message regex like "ERROR" or "WARN" to find problematic entries
4. Look for patterns: Search for specific error messages, stack traces, or module names
5. Use context for debugging: When investigating specific errors, use messageContext to see surrounding log lines (similar to rg -C)

#Examples

#Fetch All Recent Logs

const result = await fetchDeploymentLogs();
console.log(result.logs);

#Fetch Logs from Last Hour

const oneHourAgo = Date.now() - 3600 * 1000;  // Convert to milliseconds
const result = await fetchDeploymentLogs({ afterTimestamp: oneHourAgo });
if (result.found) {
    console.log(result.logs);
}

#Find Error Logs

const result = await fetchDeploymentLogs({ message: "ERROR" });
if (result.found) {
    console.log(result.logs);
} else {
    console.log("No error logs found");
}

#Find Database-Related Errors

const result = await fetchDeploymentLogs({
    message: "(?i)(database|postgres|mysql|mongo|connection.*refused)"
});
console.log(result.logs);

#Find Startup Failures

const result = await fetchDeploymentLogs({
    message: "(?i)(failed|crash|exception|traceback)"
});
console.log(result.logs);

#Find Errors with Context Lines

// Get 10 lines of context before/after each error (up to 3 matches)
const result = await fetchDeploymentLogs({
    message: "ERROR",
    messageContext: { lines: 10, limit: 3 }
});
if (result.found) {
    console.log(result.logs);
}

#Combined Time and Pattern Filter

// Get logs from the last 30 minutes containing errors
const thirtyMinAgo = Date.now() - 1800 * 1000;
const result = await fetchDeploymentLogs({
    afterTimestamp: thirtyMinAgo,
    message: "(?i)(error|exception|failed)"
});
if (result.found) {
    console.log(result.logs);
} else {
    console.log("No matching logs in the last 30 minutes");
}

#Common Log Patterns to Search For

• Any errors: "ERROR"
• Warnings and errors: "(WARN|ERROR)"
• Database issues: "(?i)database|postgres|mysql|connection"
• Network errors: "(?i)timeout|refused|unreachable"
• Authentication: "(?i)auth|token|unauthorized|forbidden"
• Memory issues: "(?i)memory|heap|oom|killed"
• Import/module errors: "(?i)import|module|cannot find"

#Troubleshooting Tips

1. No logs returned: The deployment may not have run recently, or there may be no logs matching your filter
2. Too many logs: Use the message parameter to filter, or narrow the time range
3. Looking for specific errors: Use case-insensitive regex with (?i) prefix