Logs

The Logs page shows every line your services write through a logger WizeLens reads: in a request, and outside one (startup, background jobs, timers). Filter by level, service, text, category, pattern, and where it was written.

Lines outside a request#

Lines written while no request runs are kept too, with their service and level. The Request column says "Outside a request" for them. Three options keep the volume in check. They apply only to lines outside a request; lines in a request are always kept with their trace.

Setting	.NET	Node	Environment variable	Default
Keep lines outside a request	Logs.Outside	logs.outside	WIZELENS_LOGS_OUTSIDE	on
Lowest level kept	Logs.MinLevel	logs.minLevel	WIZELENS_LOGS_MIN_LEVEL	Information / "info"
Share kept below warn (0 to 1)	Logs.SampleRate	logs.sampleRate	WIZELENS_LOGS_SAMPLE_RATE	1

Warnings and up are always kept, whatever the sample rate. Trace sampling does not apply to these lines.

createWizeLens({ serviceName: "orders-api", logs: { minLevel: "warn", sampleRate: 0.2 } });

builder.Services.AddWizeLens(o => { o.Logs.MinLevel = LogLevel.Warning; o.Logs.SampleRate = 0.2; });

Every logger WizeLens reads does this: ILogger, Serilog, and NLog on .NET; console, pino, winston, bunyan, log4js, consola, NestJS, and OpenTelemetry logs on Node. OpenTelemetry apps that send log records with no trace id to the hub or the cloud get the same treatment.

Patterns#

Log Patterns groups lines that differ only in numbers, ids, uuids, and quoted values. Job 4012 for tenant 'acme' and Job 4013 for tenant 'beta' are one pattern, Job <num> for tenant <str>. Each pattern shows its count, its share of the lines, the change against the time before, and a trend. Click a pattern to show only its lines; click it again to show them all. Patterns follow the level, service, and "written" filters.

Log metrics#

Filter the lines, then Save this search. Each saved search becomes a chart of its matching lines over the time range, with errors on top and its total against the time before. Show lines puts its filters back. The hub and the cloud keep saved searches for everyone on the project; an app's own dashboard keeps them in your browser.

Log alerts#

On the cloud, Alert on this search (or a new alert with Log lines) counts the lines that match a search over 5 minutes to 24 hours, and fires when the count is above or below your threshold:

Log lines (error and up, "timed out") is 12 (above 10)

How long logs are kept#

Logs can be kept for more or less time than traces.

• Cloud: each project has its own log retention under Team → Projects → Logs kept (1 to 400 days), or follows the organization's.
• Hub: --log-retention <time> (WIZELENS_HUB_LOG_RETENTION), else the same as --retention.

Lines outside a request are kept for the log retention. Lines in a request are kept for the log retention too, but never longer than their trace.