8 posts tagged with "Compute"

Conventional wisdom says migrating a data engine to ARM is a performance gamble you take for the discount. We ran the experiment on our own Spark compute pools, and the result inverted the premise: under 100-way concurrency, the ARM64 pool ran every job roughly twice as fast as its x86 twin — at about 20% lower infrastructure cost.

We are publishing the numbers, but also the part benchmark posts usually cut: our first measurement said ARM was 8.5x slower, and that number was wrong in a way that had nothing to do with ARM. If you are planning an ARM migration for your data platform, the detour is probably worth more to you than the table.

In The Small Job Tax we made an argument: most data platforms make you pay cluster-sized overhead for container-sized work, and your smallest jobs are quietly your most expensive per byte.

An argument is cheap. So we measured it.

One hundred Spark jobs, submitted concurrently, each one scanning ~200 MB of Iceberg data — 19 GiB of real columnar IO and 410 million rows in total — finished in 67.5 seconds, on one small compute pool that costs about $2 an hour. One hundred submitted, one hundred succeeded, zero failures.

Then we kept pushing: 200 jobs, 300, 400, 500. The pool never became the problem.

Every native execution engine for Spark arrives with the same headline: 2x, 3x, sometimes 5x faster. The benchmarks are usually real. What they rarely tell you is whether they describe your data, your table format, and your version matrix.

So we measured it ourselves. Cazpian Native Query Acceleration, against 200 million rows of Apache Iceberg data, on the Spark version we ship. We recorded wall-clock time, CPU seconds, peak memory, and — the part most benchmarks skip — whether the answers came back the same.

The result: 1.51x faster on 45% less CPU across a mixed suite, with every result identical to standard Spark. On decimal aggregation — the shape most finance and revenue reporting takes — 3.18x in the suite, and 4.14x when we later measured it end to end through the Iceberg catalog.

We also nearly published the exact opposite conclusion. Our first full round measured zero acceleration on Iceberg — not "a little", literally zero accelerated operators across five configurations. That result was real, reproducible, and completely misleading, and the reason it was wrong is worth more to you than the speedup number.

Every data engineer who has worked with Apache Iceberg at scale has hit the same wall: query performance that mysteriously degrades over time. The dashboards that used to load in two seconds now take twenty. The Spark jobs that processed in minutes now crawl for an hour. The root cause, almost always, is the same — thousands of tiny files have silently accumulated in your Iceberg tables.

The small file problem is not unique to Iceberg. But Iceberg gives you an unusually powerful set of tools to prevent it at the write layer and fix it at the maintenance layer. The catch is that most teams never configure these controls properly — or do not even know they exist.

In our previous post, we broke down the five hidden costs of running two compute engines in your lakehouse — the infrastructure duplication, the cost opacity, the metadata sync bugs, the skills fragmentation, and the governance headaches. We showed that this dual-engine tax can run $40,000+ per year for a mid-size data team.

The obvious question: why not just use Spark for everything?

The honest answer has always been: because Spark cannot deliver query results to BI tools fast enough. Not because Spark cannot execute the query — it usually can — but because the last mile of data delivery through traditional JDBC/ODBC protocols is painfully slow.

Arrow Flight SQL eliminates that bottleneck. And with it, the primary architectural reason for running a second query engine disappears.

Take an honest look at your data platform architecture. If you are running a lakehouse on AWS, there is a good chance it looks something like this: Spark clusters for ETL and data engineering, plus Trino (or Dremio, or Presto) clusters for analytics and BI queries. Two engines, two teams, two bills — all pointed at the same data.

This dual-runtime pattern has become the default architecture for most modern data platforms. And on the surface, it makes sense. Spark is great at processing data. Trino is great at querying it. Each engine solves a real problem.

But running two engines has hidden costs that most organizations never quantify — and once you add them up, the number is hard to ignore.

In Part 1 of this series, we exposed the Small Job Tax — the hidden cost of cold starts, overprovisioned clusters, and per-job infrastructure overhead that silently drains data budgets. We showed that for many teams, more than half of their Spark compute spend goes to infrastructure bootstrapping, not actual data processing.

The natural follow-up question: what if you could eliminate that overhead entirely?

That is exactly what Cazpian Compute Pools are built to do.

Most data teams obsess over optimizing their biggest, most complex Spark jobs. Meanwhile, hundreds of tiny ETL jobs — each processing a few gigabytes — quietly rack up a bill that nobody questions.

We call it the Small Job Tax: the disproportionate cost of running lightweight workloads on infrastructure designed for heavy lifting. And for many organizations, it is the single largest source of wasted compute spend.