Streaming #

Search on Pizza is real-time — documents are visible the moment they are written. The stream block makes a single search request behave like a subscription: the engine keeps the query warm and pushes fresh hits as they land, instead of making the client poll.

POST /my-collection/_search

Example #

This page has no live playground demo: the response body here is a live HTTP stream (chunked, newline-delimited hits), while the in-page widget executes one-shot queries against a WebAssembly engine and renders a complete JSON result. Run the example with curl against a live server to watch chunks arrive incrementally.

{
  "query": { "match": { "field": "message", "query": "error" } },
  "size": 0,
  "stream": {
    "mode": "progressive",
    "buffer_size": 4,
    "max_wait_ms": 250
  }
}

Parameters #

• mode
  (Required, batch | progressive | threshold) Delivery mode:
  • batch — normal one-shot search; the block only configures timing.
  • progressive — flush partial results as the query makes progress, then keep pushing newly matching documents.
  • threshold — hold results back until a score threshold or wait budget is met, trading freshness for stability.
• buffer_size
  (Optional, integer, default: 4) Micro-batching of pushed hits — more is cheaper per hit, less is lower latency.
• score_threshold
  (Optional, float) In threshold mode, the score a hit must reach before the buffer flushes.
• max_wait_ms
  (Optional, integer) Upper bound on how long a partially filled buffer may wait before flushing regardless.
• aggs_priority
  (Optional, normal | low | deferred) Whether aggregations in the same request block streaming delivery. deferred ships hits first and fills in aggregation results later.

Notes #

• Streaming interacts with realtime visibility: a hit can arrive in the same request that indexed it — there is no refresh interval to wait for.
• Cursors (search_after) combine with streaming for durable consumption; the change feed is the complementary write-path stream (CDC).
• Keep buffer_size small for alerting-style consumers and large for dashboard-style consumers.