Who Posts Unavailable Blobs?
Question
Which entities submit blob transactions that aren't available to nodes when blocks arrive, and how prevalent is this behavior across L2s?
Background
Blob transactions are typically broadcast to the public mempool before being included in blocks. This investigation examines which blobs were not available to our reference nodes when blocks arrived.
Propagation categories:
- Full Propagation - All observing nodes had the blob in their mempool when the block arrived
- Partial Propagation - Some nodes had it, some did not
- Unavailable - No node had the blob in their mempool when the block arrived
Investigation
Important methodology note: We monitor blob availability across 7870 reference nodes via engine_getBlobsV2. From a practical standpoint, if a blob isn't available to nodes when the block arrives it's effectively the same as if the blob was never in the public mempool for this node since these nodes were not able to take advantage of the engine_getBlobsV2 API. This doesn't necessarily mean the blob was never in the public mempool, only that it wasn't in the mempool on any of our nodes at the time the block was received.
Overall Blob Availability
How many blobs were available to our reference nodes when blocks arrived?
View Query: who_posts_private_blobs_totals
Unavailable Rate (Top 15 by Volume)
Looking at the top 15 blob posters by volume, we can compare unavailable rates fairly.
View Query: who_posts_private_blobs_rate
The table above shows unavailable rates for top blob posters. High-volume L2s like Base and World Chain have low unavailable rates when normalized, while several major L2s have 0% unavailable rates.
Empty Rate by Submitter
Beyond completely unavailable blobs, what percentage of nodes are missing each submitter's blobs when blocks arrive?
View Query: who_posts_private_blobs_summary
The "empty rate" is the average percentage of nodes that did not have a blob when the block arrived. Higher = worse propagation.
Takeaways
- Completely unavailable blobs are rare: the vast majority of blobs are available to our 7870 reference nodes when blocks arrive
- These blobs may have eventually reached the public mempool, but from our nodes' perspective they were effectively private since they weren't available in time for block verification
- Absolute counts are misleading: High-volume L2s may have more unavailable blobs in absolute terms, but very low rates when normalized by volume
- Several major L2s have 0% unavailable rates, showing that good mempool propagation is achievable
- Partial availability is common, with most blobs reaching some nodes but not others, especially for high-volume L2s