---
title: "Troubleshoot Cloud Logs write issues | Grafana Cloud documentation"
description: "How to troubleshoot Cloud Logs write failures."
---

# Troubleshoot Cloud Logs write issues

Unfortunately, occasionally logs are rejected and write failures occur. This can be for a number of reasons; determining the reason for write failures can be challenging.

Because Loki has detailed information about write failures and can emit them through logs, Cloud Logs users can see write errors in a self-service fashion. However, there are limitations to what errors Loki can log. The following are example of errors that cannot be diagnosed with this feature:

- If the push request is too big (for example, 1GB). Grafana cloud would reject the request before it reaches Loki, so it would never be logged.
- Alloy internal issues, for example, the agent running out of memory. Client-side issues wouldn’t be discovered because the request would never reach Grafana Cloud to be logged by Loki.

To troubleshoot logs write issues:

1. [Log in](/auth/sign-in) to your GrafanaCloud instance.
2. Click the menu icon, then click the Explore (compass) icon.
3. From the menu in the top left of the Explore page, select the `grafanacloud-[instanceName]-usage-insights` datasource.
4. Query the datasource for write issues.

<!--THE END-->

- Use the [Query Builder](/docs/grafana-cloud/connect-externally-hosted/data-sources/prometheus/query-editor/) on the **Builder** tab.
- Or, click the **Code** tab and enter your query in the field. Example queries:

![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```none
 {instance_type="logs"} |= "path=write"
 {instance_type="logs"} |= "push request failed"
```

The query returns log messages, which include information to help determine why the log write failed. The log messages include which stream discarded logs, for what reason, and provides valid values.

> Note
> 
> You can also troubleshoot write issues with Dashboards.

The following sections contain the errors that can be discovered using this feature and the message displayed in the logs.

## Entry too far behind

**[Entry too far behind](/docs/loki/next/operations/request-validation-rate-limits/#too_far_behind-and-out_of_order):** “entry too far behind, oldest acceptable timestamp is: %s”

This validation error is returned when a stream is submitted out of order. This problem can be solved by ensuring that log delivery is configured correctly. It should also be noted that this a per-stream error, so by simply splitting streams (adding more labels) this problem can be circumvented, especially if multiple hosts are sending samples for a single stream.

In Grafana Cloud, unordered writes can only be accepted up to 1 hour behind the most recent timestamp sent. For example, if `max_chunk_age` is 2 hours and the stream `{foo="bar"}` has one entry at `8:00`, Loki will accept data for that stream as far back in time as `7:00`. If another log line is written at `10:00`, Loki will accept data for that stream as far back in time as `9:00`.

> Tip
> 
> If you want to load older logs into Loki, you need to do so in a roughly chronological order, you can playback logs from years ago as long as you start with the older logs and work your way forward to the most current logs. For example, if today is 2025-05-25, as long as you have `reject_old_samples: false` you can send a log with timestamp `2018-01-01T13:00:00Z`. The same rules apply though, if that’s the most recent log for the stream you can only send older logs that have a time newer than `2018-01-01T12:00:00Z` (you can send anything newer).
> 
> Make sure you have a schema entry that has a `from` date older than the oldest logs you want to send.

## Entry too far in the future

**[Entry too far in the future](/docs/loki/next/operations/request-validation-rate-limits/#too_far_in_future):** “entry for stream ‘%s’ has timestamp too new: %v”

This error can be solved by increasing the `creation_grace_period` value, or investigating why this particular stream has a timestamp too far into the future. The stream in question will be returned in the body of the HTTP response.

## Entry too old

**Entry too old:** “entry for stream ‘%s’ has timestamp too old: %v, oldest acceptable timestamp is: %v”

This error means that the timestamp for the log is greater than the `reject_old_samples_max_age` value; the default value is one week.

## Duplicate label names

**[Duplicate label names](/docs/loki/next/operations/request-validation-rate-limits/#duplicate_label_names):** “stream ‘%s’ has duplicate label name: ‘%s’”

This error can be solved by removing one of the identical labels.

## Invalid labels

**[Invalid labels](/docs/loki/next/operations/request-validation-rate-limits/#invalid_labels):** “Error parsing labels ‘%s’ with error: %s”

Check that your labels are valid. Label names may contain ASCII letters, numbers, as well as underscores. They must match the regex `[a-zA-Z_][a-zA-Z0-9_]*`. Label names beginning and ending with double underscores `__` are reserved for internal use.

## Label name too long

**[Label name too long](/docs/loki/next/operations/request-validation-rate-limits/#label_name_too_long):** “stream ‘%s’ has label name too long: ‘%s’”

The default value for `max_label_name_length` is 1024 characters. You can use [logcli](/docs/loki/next/query/logcli/getting-started/#logcli-example-queries) to print a list of all your labels and their unique values: `logcli series '{cluster="vinson"}' --analyze-labels`.

## Label value too long

**[Label value too long](/docs/loki/next/operations/request-validation-rate-limits/#label_value_too_long):** “stream ‘%s’ has label value too long: ‘%s’”

The default value for `max_label_value_length` is 2048 characters. This setting also applies to the metric name. Check the lengths of your label names, or remove one or more labels from the log stream.

## Line too long

**[Line too long](/docs/loki/next/operations/request-validation-rate-limits/#line_too_long):** “Max entry size ‘%d’ bytes exceeded for stream ‘%s’ while adding an entry with length ‘%d’ bytes”

The default value for `max_line_size` is `256k`. Either reconfigure your client to truncate log lines that are too long, or you can use the [configuration self-serve API](/docs/grafana-cloud/send-data/logs/config-self-serve/#set-max-line-truncation) to set `max_line_size_truncate` to `true`.

## Max label names per series

**[Max label names per series](/docs/loki/next/operations/request-validation-rate-limits/#max_label_names_per_series):** “entry for stream ‘%s’ has %d label names; limit %d”

The maximum label names per series is 15. This error can be solved by removing one or more labels until you are below the limit.

## Missing labels

**[Missing labels](/docs/loki/next/operations/request-validation-rate-limits/#missing_labels):** “error at least one label pair is required per stream”

Add at least one label to your logs to define a log stream.

## Rate limited

**[Rate limited](/docs/loki/next/operations/request-validation-rate-limits/#rate_limited):** “Ingestion rate limit exceeded for user %s (limit: %d bytes/sec) while attempting to ingest ‘%d’ lines totaling ‘%d’ bytes, reduce log volume or contact your Loki administrator to see if the limit can be increased”

Contact Grafana Support to see if the limit can be increased.

## Stream limit

**[Stream limit](/docs/loki/next/operations/request-validation-rate-limits/#stream_limit):** “Maximum active stream limit exceeded, reduce the number of active streams (reduce labels or reduce label values), or contact your Loki administrator to see if the limit can be increased”

Contact Grafana Support to see if the limit can be increased.

> Note
> 
> For Grafana Cloud Logs customers, the “Loki administrator” is Grafana Support. If you would like to inquire about increasing a rate limit, please [file a support ticket](/profile/org/tickets/new).