BNB Chain sets hard deadline for node upgrade ahead of April 28 Osaka/Mendel fork
BNB Chain has issued a strict warning to all node operators: upgrade to BSC v1.7.2 before the Osaka/Mendel hard fork hits mainnet on April 28, or risk your node falling out of sync with the network.
The protocol upgrade, scheduled for April 28 at 2:30 a.m. UTC, is not a routine update that can be postponed. According to BNB Chain developers, the switch to BSC v1.7.2 is mandatory for any operator who wants to keep their node aligned with the canonical BNB Smart Chain (BSC) after the fork.
Mandatory move to BSC v1.7.2
In its latest notice, the BNB Chain team instructed node operators to:
– Upgrade their node software to BSC v1.7.2
– Correctly replace existing binaries with the new version
– Remove deprecated or obsolete configuration parameters from their setups
These steps are essential to prevent nodes from “losing sync” with the chain while the Osaka/Mendel fork is being activated. If operators skip or partially complete the process, their nodes may continue running – but on an incompatible version of the protocol, effectively isolating them from the live network.
The emphasis on properly cleaning up old configuration fields highlights that this is not just a simple version bump. Legacy settings that conflict with the new rules can cause subtle bugs, stalled blocks, or full desynchronization once the hard fork rules take effect.
Focus on infrastructure readiness
The message from BNB Chain clearly centers infrastructure readiness as the top priority in the run‑up to Osaka/Mendel. With the mainnet cutoff time fixed, there is no flexibility: nodes that have not upgraded in time will not be able to validate or reliably relay transactions under the new rules.
This is especially critical for validators and major infrastructure providers. Any downtime or consensus issues at the time of the fork can impact block production, transaction finality, and the broader reliability of the network. The chain’s operators are effectively being told: if you want to participate in the post‑fork BSC, you must be on v1.7.2 before the switch happens.
From testnet to mainnet: Osaka/Mendel rollout
The Osaka/Mendel hard fork has already been deployed to the BSC testnet. It was activated there on March 24 at block 88,379,325, giving developers and infrastructure teams a testing ground to validate changes before the mainnet rollout.
According to developers, the testnet phase helped improve four core aspects of the network:
– Block construction quality
– Handling of high transaction volumes at scale
– Overall network stability under load
– Execution accuracy for complex transactions and new transaction types
With those tests completed and issues addressed, the network is now transitioning from “preparation mode” to full mainnet activation. That transition puts additional pressure on node operators to be fully aligned and ready, since testnet issues can be tolerated, but mainnet disruptions are far more costly.
Mendel’s core change: hard gas cap via BEP‑652
One of the headline features of the Mendel upgrade is the introduction of BEP‑652, which integrates Ethereum’s EIP‑7825 into BNB Chain. This proposal enforces a protocol‑level gas cap per transaction, set at 16,777,216 gas units.
Before this change, BNB Chain used a softer, more flexible model for gas limits. Operators could effectively treat soft caps differently, leading to inconsistent behavior between nodes and potential edge cases. With BEP‑652, the gas limit becomes hard and uniform at the protocol level:
– Every node on the network must reject any transaction that requires more than 16,777,216 gas.
– The rejection behavior is deterministic and identical across all properly updated nodes.
This shift to a strict cap is designed to make transaction processing more predictable and reduce the risk that transactions behave differently depending on which node or validator processes them.
Broader upgrade: nine BEPs and Ethereum alignment
Osaka/Mendel is not just about a single BEP. In total, the upgrade packages nine BNB Evolution Proposals (BEPs) into the fork. As part of this bundle, BNB Chain also integrates a subset of Ethereum improvement proposals associated with the Fusaka upgrade.
Out of 13 Ethereum proposals tied to Fusaka, BNB Chain has adopted seven:
– Six of those required a hard fork, meaning they change consensus or protocol behavior in a way that all nodes must adopt simultaneously.
– One involved a client‑side change to remote procedure call (RPC) handling, impacting how nodes communicate with wallets and external tools.
The remaining six Ethereum proposals were not adopted, with BNB Chain developers citing architectural differences between Ethereum and BSC. Instead of mirroring Ethereum wholesale, BNB Chain selectively integrated only the changes that fit its own performance goals and design constraints.
In addition, two new BNB Chain‑specific upgrades have been introduced via:
– BEP‑657
– BEP‑648
These are tailored specifically for BNB Chain’s architecture and performance profile rather than directly copying Ethereum behavior.
BEP‑657: controlling blob transaction inclusion
BEP‑657 focuses on how and when “blob” transactions can be included in blocks. Under this proposal, blob transaction inclusion is constrained based on block numbers.
The change effectively gives the protocol finer control over the rollout and behavior of these specialized transaction types. By tying blob transaction rules to block height, developers can:
– Gradually phase in new transaction formats
– Avoid sudden spikes in resource usage
– Maintain network stability as more complex data or execution paths are introduced
For node operators, this means that after the Osaka/Mendel fork, their clients must correctly enforce new logic around which blocks can or cannot include blob transactions – one more reason the BSC v1.7.2 update is non‑negotiable.
BEP‑648: lower latency, faster finality
BEP‑648 targets network performance, with a focus on reducing latency and improving the speed at which transactions become final.
By optimizing how blocks propagate and how consensus is reached, BEP‑648 aims to:
– Shorten the time between transaction broadcast and inclusion
– Tighten the window for potential chain reorganizations
– Deliver a more responsive user experience for dApps, traders, and everyday users
For validators and node operators, this upgrade may involve more stringent timing behavior, improved communication patterns, or new assumptions about block intervals and confirmation depth. Again, remaining on outdated software after Osaka/Mendel would mean missing these optimizations and potentially behaving unpredictably relative to the rest of the network.
Why missing the deadline is risky for node operators
Failing to complete the upgrade on time can have significant consequences:
– Desynchronization: Nodes running older binaries or configurations may no longer be able to follow the canonical chain once the fork rules activate.
– Consensus issues: Validators that do not understand the new rules risk producing invalid blocks, which the updated network will reject.
– Economic penalties: Depending on a validator’s role and staking setup, repeated invalid blocks or downtime during the fork may result in lost rewards or damaged reputation.
– Operational instability: Even non‑validator nodes could suffer from stalled processes, increased error logs, and broken services that depend on consistent RPC responses.
For infrastructure providers, exchanges, wallets, and DeFi platforms, an out‑of‑date node at the time of a hard fork can translate into user‑visible outages, misreported balances, or failed transactions.
Practical steps for a safe Osaka/Mendel upgrade
To minimize risk, node operators should treat Osaka/Mendel like a mission‑critical deployment. A robust approach typically includes:
1. Staging and testing
– First deploy BSC v1.7.2 on a staging or internal environment.
– Sync against testnet or a read‑only mainnet mirror if possible.
– Verify that core services (RPC endpoints, monitoring, alerting, logs) behave as expected.
2. Configuration review
– Compare your current configuration files to the new version’s defaults.
– Remove deprecated fields flagged by the BNB Chain team.
– Double‑check custom settings related to gas limits, transaction pools, and networking.
3. Backup and rollback planning
– Take snapshots or backups of node data and configurations before upgrading.
– Prepare a documented rollback plan in case of unforeseen issues, while keeping in mind that rolling back across a hard fork boundary is often not viable.
4. Monitoring the upgrade window
– Schedule technical staff to be on call during and shortly after the fork time (2:30 a.m. UTC on April 28).
– Monitor for unusual log entries, missed blocks, or divergence from trusted reference nodes.
5. Post‑fork verification
– Confirm that the node is following the correct chain by comparing block hashes with trusted peers.
– Run sanity checks on RPC calls, transaction submissions, and block propagation.
Impact on dApps, users, and the broader ecosystem
While the mandatory upgrade primarily targets node operators, its effects will cascade across the ecosystem:
– dApp developers may need to ensure their contracts and off‑chain services respect the new gas cap. Transactions that were previously close to upper gas bounds could now be rejected outright if they exceed 16,777,216 gas.
– Users interacting with complex protocols, such as DeFi platforms or NFT marketplaces, might notice changes in gas usage patterns. Some operations could be refactored or broken into multiple transactions to stay under the cap.
– Exchanges and custodians must confirm that their internal infrastructure is fully synced and upgraded to avoid misaligned balances or delayed deposits and withdrawals during the fork window.
Because the gas cap is enforced uniformly by all compliant nodes, wallet providers and front‑ends will likely adjust their interfaces to prevent users from even attempting transactions that would exceed the protocol limit.
Strategic significance of adopting selected Ethereum proposals
BNB Chain’s decision to adopt only seven of the 13 Fusaka‑related Ethereum proposals underscores a broader strategy: remain compatible enough with Ethereum to benefit from tooling, expertise, and developer familiarity, while still optimizing the protocol for BNB Chain’s specific performance and scalability goals.
By bringing over only the proposals that fit its architecture, BNB Chain:
– Keeps a path open for cross‑ecosystem tooling and migration.
– Avoids inheriting design trade‑offs that may not align with its own priorities.
– Maintains the flexibility to introduce bespoke BEPs like 657 and 648, which are tuned for its own throughput and finality requirements.
For developers building on BNB Chain, this selective adoption means they get many of the benefits of Ethereum’s evolution, but still need to be aware of BSC‑specific behavior when designing high‑performance or gas‑intensive applications.
What comes next after Osaka/Mendel
Once the Osaka/Mendel hard fork successfully hits mainnet and the network stabilizes, attention is likely to shift toward:
– Real‑world performance of BEP‑648’s latency and finality improvements.
– How the hard gas cap affects contract design patterns and layer‑two or sidechain strategies within the BNB ecosystem.
– Additional protocol‑level refinements that may build on the groundwork laid by BEP‑652, BEP‑657, and the adopted Ethereum proposals.
If the upgrade proceeds smoothly, it will reinforce BNB Chain’s ability to coordinate complex hard forks involving multiple BEPs and cross‑ecosystem standards. If issues arise, they will likely inform how future upgrades are staged, tested, and communicated.
Bottom line for operators
For now, the core message is simple and time‑sensitive:
Node operators on BNB Chain must upgrade to BSC v1.7.2, replace binaries properly, and remove outdated configuration fields before the Osaka/Mendel hard fork at 2:30 a.m. UTC on April 28.
Compliance with these instructions is essential to remain in sync with the network and to fully participate in the new protocol rules introduced by the Osaka/Mendel upgrade.