BitShares block production incident

An incident occurred on the BitShares network and caused an unplanned interruption of block production
10 July 2017   3120
BitShares

Is a software company working on financial solutions built on a blockchain, such as decentralized asset exchanges, banking, project funding

On Monday, July 10th, a software company BitShares faced an incident occurred on the BitShares network that caused an unplanned interruption of block production.

As the company reports in the official announcement, all block producers have been affected by a memory corruption that was caused by an automatic resize of a flat_index container that resulted in an unrecoverable stale state. This has happened for the first time in over two years of blockchain operations.

Blockchain

Distributed database that is used to maintain a continuously growing list of records, called blocks

Luckily, after several core developers debugging the code, the cause was identified and a patch was quickly delivered to the block producers. Shortly after that, the blockchain recovered and new blocks have been generated. All transaction that made it into the blockchain prior to this incident were unaltered.

The team argues that it is absolutely necessary that everyone is aware that the nature of the patch requires all nodes to apply the patch, accordingly, in order to sync back with the blockchain. The exchanges and third party providers are to update their back-end to tag 2.0.170710 and rebuild. The following steps facilitate this update:

git fetch
git checkout 2.0.170710
git submodule update --init --recursive
make

As it turned out after further investigation, the root cause was an inappropriate implementation of flat_index::remove that only zeroed an entry instead of removing the whole element from the container, BitShares team detailed. What happens is that a new bitasset has been proposed but the proposal wasn’t fully approved. The bitasset data was created in the database and then zeroed instead of being removed after expiration of the proposal. This is the first time in the history of the chain when flat_index::remove was called.

The conclusion is that flat_index is not made for having items removed. Proposals can always lead to items being removed, which means that flat_index is not suitable for the job and should be replaced in all places. 

Wirex to Issue 26 Stablecoins on XLM Blockchain

Wirex chosen Stellar blockchain because company considers it safe, easily scalable and relatively inexpensive to use
25 April 2019   66

British online banking platform Wirex has announced the listing for the XLM token, as well as the release of 26 stablecoins on the Stellar blockchain, pegged to fiat currencies, including USD, EUR, GBP, HKD and SGD.

Prior to this, Wirex card supported eight digital assets and ten fiat currencies.

In addition, Wirex added the ability to instantly convert steablecoins to each other at over-the-counter rates.

As the company expects, new assets will be used for money transfers, issue and redemption of tokens, as well as for payments for services.

The choice of Wirex fell on the Stellar blockchain, as the company considers it safe, easily scalable and relatively inexpensive to use.

Last year Wirex became the third company in a row that received a license to provide services in the UK and Europe.