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    Simple Log Service:Query and analysis

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    Simple Log Service:Query and analysis

    Last Updated:Jun 10, 2026

    Lists the query and analysis limits for Logstores and Metricstores in Simple Log Service (SLS).

    Logstore

    Queries

    Item

    Description

    Number of keywords

    Up to 30 conditions per query, excluding logical operators.

    Field value size

    Maximum single field value size: 512 KB. Content beyond this limit is not indexed.

    Logs with field values exceeding 512 KB may not appear in keyword searches, but the log data remains intact.

    Note

    To configure the maximum field value length, see Why are field values truncated during query and analysis?

    Concurrent operations

    A single project supports up to 100 concurrent queries.

    For example, 100 users can query different logstores in the same project simultaneously.

    Returned results

    Up to 100 results per page. Navigate pages to view all results.

    Fuzzy search

    During a fuzzy search, Simple Log Service matches up to 100 terms and returns logs containing those terms that meet the search criteria. Fuzzy search.

    Result sorting

    Results are sorted by time in descending order, accurate to the second or nanosecond.

    Analysis

    Limit

    General-purpose instance

    Dedicated SQL

    SQL enhancement

    Full Precision

    Concurrency

    Up to 15 concurrent queries per project.

    Up to 100 concurrent queries per project.

    Up to 5 concurrent queries per project.

    Data volume

    Up to 400 MB per query (excluding cached data). Excess data is truncated with an incomplete query result marker.

    Up to 2 GB per query (excluding cached data). Excess data is truncated with an incomplete query result marker.

    Unlimited.

    Enabling the mode

    Enabled by default.

    Enable via toggle. SQL enhancement.

    Enable via toggle. SQL complete accuracy.

    Fee

    Free of charge.

    Charged based on the actual CPU time used.

    Charged based on the actual CPU time used.

    Data effectiveness

    Applies only to data written after the feature is enabled.

    To analyze historical data, you must reindex the data.

    Applies only to data written after the feature is enabled.

    To analyze historical data, you must reindex the data.

    Applies only to data written after the feature is enabled.

    To analyze historical data, you must reindex the data.

    Return results

    By default, a query returns up to 100 rows and 100 MB. Queries exceeding 100 MB return an error.

    To return more data, use the LIMIT clause.

    By default, a query returns up to 100 rows and 100 MB. Queries exceeding 100 MB return an error.

    To return more data, use the LIMIT clause.

    By default, a query returns up to 100 rows and 100 MB. Queries exceeding 100 MB return an error.

    To return more data, use the LIMIT clause.

    Field value size

    Default maximum field value length is 2 KB (2,048 bytes), configurable up to 16 KB (16,384 bytes). Content exceeding the limit is excluded from analysis and retrieval.

    Note

    To change the limit, set Maximum Length of Text Field. The updated setting applies only to incremental data. Create an index.

    Default maximum field value length is 2 KB (2,048 bytes), configurable up to 16 KB (16,384 bytes). Content exceeding the limit is excluded from analysis and retrieval.

    Note

    To change the limit, set Maximum Length of Text Field. The updated setting applies only to incremental data. Create an index.

    Default maximum field value length is 2 KB (2,048 bytes), configurable up to 16 KB (16,384 bytes). Content exceeding the limit is excluded from analysis and retrieval.

    Note

    To change the limit, set Maximum Length of Text Field. The updated setting applies only to incremental data. Create an index.

    Timeout period

    Maximum timeout: 55 seconds.

    Maximum timeout: 55 seconds.

    Maximum timeout: 55 seconds.

    Number of bits for double-typed field values

    Maximum 52 bits for double-typed field values.

    Floating-point numbers encoded with more than 52 bits lose precision.

    Maximum 52 bits for double-typed field values.

    Floating-point numbers encoded with more than 52 bits lose precision.

    Maximum 52 bits for double-typed field values.

    Floating-point numbers encoded with more than 52 bits lose precision.

    Metricstore

    Limit

    Description

    Notes

    API list

    Only the /query, /query_range, /labels, /label/{label}/values, and /series API operations are supported.

    Data specifications

    1. The metric name must match the regular expression [a-zA-Z_:][a-zA-Z0-9_:]*.

    2. The label key must match the regular expression [a-zA-Z_][a-zA-Z0-9_]*. The label value cannot contain a VERTICAL LINE (|). No other limits apply.

    For other limits, see Metric.

    Concurrent queries

    A single project supports a maximum of 15 concurrent query operations.

    Example: 15 users can query different Metricstores in the same project simultaneously.

    Data read volume

    A single shard can read up to 2 million time series, 2 million data points, or 200 MB per request. The read stops when any limit is reached.

    When a limit is reached, an "incomplete read" status is returned. To handle larger data volumes, split shards.

    Data volume for computing

    Before running a PromQL calculation, the raw data volume on a single node is checked. The limit is 200 million time series, 200 million data points, or 2 GB per calculation. Exceeding any limit returns an error.

    To aggregate large data volumes in a single execution, enable concurrent computing. For more information, see Concurrent computing.

    Data points for computing

    The PromQL engine performs a point selection during calculation. If selected data points exceed 50 million, an error is returned.

    This matches open-source Prometheus limits. For aggregation queries, use concurrent computing.

    Query queue length

    Incoming requests enter an execution queue. If the queue exceeds 200 tasks, subsequent requests are discarded.

    A burst of high-QPS requests may cause some requests to be denied.

    Query results (PromQL)

    The /query_range API returns up to 11,000 data points per time series (per the open-source protocol). If (end - start)/step > 11000, an error is returned.

    For queries over a long time range, increase the step size parameter as needed.

    Query results (SQL)

    A single SQL query or calculation returns up to 100 rows by default, or up to 1 million rows with a "limit all" clause. This applies to:

    1. Directly query raw time series data with SQL.

    2. Nest a PromQL subquery in SQL for calculations.

    One million rows equal one million data points. Query syntax: Syntax for time series data query and analysis.

    Nesting PromQL subqueries in SQL

    The length of a PromQL statement is limited to 3,000 characters.

    For information about the query syntax, see Syntax of query and analysis on metric data.

    Remote Read API

    The Remote Read API returns up to 1 GB per request. Maximum query span: 30 days.

    Note

    The Remote Read API pulls all raw data and consumes significant Metricstore memory. Concurrent requests are limited to 10. Avoid this API in production. Use the Metricstore query API instead, or export raw data through data transformation, data shipping, or data consumption and export.

    The maximum query time span cannot be adjusted.

    Open-source documentation: Prometheus Remote Read.

    Note

    Set the lookback-delta of your local Prometheus to 3 minutes when using the Remote Read API. This matches the Metricstore default. Otherwise, query results may be incomplete.

    lookback-delta

    In SLS Metricstore, this parameter defaults to 3 minutes.

    lookback-delta is a PromQL-specific parameter. Details: lookback-delta.

    The PromQL API supports custom values up to 3 days. For information about how to configure custom settings, see Time series metric query APIs.

    Timeout

    Default timeout: 1 minute for PromQL API queries, 55 seconds for SQL queries.

    The PromQL API supports custom settings. For information about how to configure custom settings, see Time series metric query APIs.

    Limits on Meta APIs

    Meta APIs query up to 5 minutes of data to ensure performance. This applies to the /labels, /label/{label}/values, and /series API operations.

    The 5-minute window spans [end - 5min, end].

    The PromQL API supports custom start and end times for Meta APIs. For information about how to configure the settings, see Query series API.

    Note

    By default, Meta APIs query all data. Set a match parameter to narrow the query and improve performance. For more information, see Query series API.