Logging

This guide will go over how the GLIDE clients logger works and how to configure it.

How Logging Works

Valkey GLIDE clients are built upon a shared, high-performance Rust Core that utilizes a singleton logger exposed via the Foreign Function Interface (FFI). This architecture allows client wrappers to configure the logger and push their own messages directly into the core, ensuring that all logs remain synchronized and preserve the order of events.

Currently, GLIDE does not support direct integration with third-party logging libraries. While there is interest in adding this capability, it has not yet been prioritized. If this functionality is critical for your use case, we encourage you to submit a feature request to the Valkey GLIDE GitHub.

The logger is currently only available for Python, Node, and Java clients.

Examples

The following examples show how to configure the logger in GLIDE clients.

Python

import asyncio
from glide import GlideClientConfiguration, NodeAddress, GlideClient, Logger, LogLevel

async def test_cluster_client():
    # Configure the log level and the log file name
    Logger.set_logger_config(level = LogLevel.DEBUG, file_name="./glide_logs")

    # Logging example
    Logger.log(log_level=LogLevel.INFO, log_identifier= "LoggingExample", message = "Hello World!")

    # Standalone client configuration
    addresses = [NodeAddress("localhost", 6379)]
    config = GlideClientConfiguration(addresses)
    client = await GlideClient.create(config)
    await client.ping()

asyncio.run(test_cluster_client())

Refer to the API reference for the full logger interface.

Node

import { GlideClient, Logger } from "@valkey/valkey-glide";

// Configure the log level and the output file name.
Logger.setLoggerConfig("debug", "./glide_logs");

// Logging example
const message = "Hello World!";
const identifier = "LoggingExample";
Logger.log("info", identifier, message);

// Standalone client configuration
const addresses = [{ host: "localhost", port: 6379 }];
const client = await GlideClient.createClient({
  addresses: addresses,
});

await client.ping();

Refer to the API reference for the full logger interface.

Java

package com.example;

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

import glide.api.GlideClient;
import glide.api.logging.Logger;
import glide.api.models.configuration.GlideClientConfiguration;
import glide.api.models.configuration.NodeAddress;

public class ValkeyPingExample {

    public static void main(String[] args) {

        // Configure the log level and the output file name.
        String logFile = "./glide_logs";
        Logger.setLoggerConfig(Logger.Level.DEBUG, logFile);

        // Logging example
        String identifier = "LoggingExample";
        Logger.log(Logger.Level.INFO, identifier, "Hello World!");

        String host = "localhost";
        Integer port = 6379;
        GlideClientConfiguration config =
            GlideClientConfiguration.builder()
                    .address(NodeAddress.builder().host(host).port(port).build())
                    .build();

        // Create a standalone client
        try (GlideClient client = GlideClient.createClient(config).get()) {
            CompletableFuture<String> result = client.ping();
        } catch (ExecutionException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

Refer to the API reference for the full logger interface.

Log Files

By default, logs are output to stdout. However, you can configure the logger to write logs to a file by specifying a file name in the configuration methods shown in the examples above.

If the file name is an absolute path /example/logs/client_logs, the logs will be written to the file /example/logs/client_logs.<timestamp>.

If the file name is a relative path ./client_logs, the logs will be written inside the folder glide-logs. For example, ./glide-logs/client_logs.<timestamp>.

To prevent large files, log files are rotated hourly.

Cleanup Outputs

Since logs are outputted from the Rust layer, it contains ANSI color code for console outputs. These codes may appear in log files as unknown characters or character codes. To disable these color codes, you can set the environment variable NO_COLOR=1 before starting the logger.