Clickhouse Queries

Overview

Clickhouse is used for observability in LangDB. It provides high-performance analytics capabilities that allow us to track and analyze system behavior, performance metrics, and user activities across the platform.

Table Schemas

Traces Table

The following create query represents thetracestable that stores distributed tracing information of Langdb AI Gateway.

CREATE TABLE IF NOT EXISTS langdb.traces
(
    trace_id        UUID,
    span_id         UInt64,
    parent_span_id  UInt64,
    operation_name  LowCardinality(String),
    kind            String,
    start_time_us   UInt64,
    finish_time_us  UInt64,
    finish_date     Date,
    attribute       Map(String, String),
    tenant_id       Nullable(String),
    project_id      String,
    thread_id       String,
    tags            Map(String, String),
    parent_trace_id Nullable(UUID),
    run_id          Nullable(UUID)
)
ENGINE = MergeTree
ORDER BY (finish_date, finish_time_us, trace_id)
SETTINGS index_granularity = 8192;

-- Add bloom filter index for thread_id
ALTER TABLE langdb.traces ADD INDEX idx_thread_id thread_id TYPE bloom_filter GRANULARITY 4;

-- Add composite index for tenant_id, project_id, and operation_name
ALTER TABLE langdb.traces ADD INDEX idx_tenant_projec

Common Filters

• thread_id field with its dedicated bloom filter index allows for efficient filtering of traces based on specific execution threads.

• The run_id field enables filtering and grouping traces by specific execution runs.