31 votes
Accepted

Without the Coordinator, how will the network decide which double-spend succeeds?

In every DLT, a transaction have a probability to be valid. (In Bitcoin, a transaction is valid as long as it is written in the longest chain, so the probability for your transaction to be invalid is ...
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  • 5,344
7 votes
Accepted

What is the Actual IOTA Algorithm for Tip Selection?

(I already know that this answer will disappoint you - as it did disappoint me when I found it out) The current algorithms around the tangle depend on a central node run by the Foundation, known as ...
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  • 7,254
5 votes

Is the tip selection algorithm run only on full nodes?

Currently the tip selection is only performed on full nodes, and cannot be performed on light nodes. This is not only true for the tip selection, but also for broadcasting transactions and for ...
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  • 7,254
4 votes

What are tips and what is the tip selection algorithm?

In IOTA, every new (unconfirmed) transaction is known as a tip. These tips should each reference two previous transactions. Choosing which tips to extend is decided by a Random Walk Monte Carlo ...
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4 votes
Accepted

When are unconfirmed transactions forgotten?

They will get removed (together with the confirmed transactions) at the next snapshot. Permanodes will keep them forever (if they have ever seen them; it is not guaranteed for unconfirmed ...
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  • 7,254
3 votes

Tip selections and acceptance

Selecting 2 random tips will impact negatively the probability for your transaction to be confirmed by others. There are multiple reasons for that: There is a chance that 2 randomly selected tips are ...
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  • 5,344
3 votes
Accepted

Is it intended that getTransactionsToApprove can possibly return non-tips as well?

First of all, the property of a transaction being a tip is volatile and can change before the walk even finishes. So even if the function was guaranteed to find a tip, by the time it returned it could ...
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  • 7,254
3 votes
Accepted

How does IOTA detect inconsistency?

This error message was removed in April 2017. Thats the reason why you can't find it. You can fix the issue by deleting your local database. Take a look here. The code which contains this error ...
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  • 1,607
3 votes
Accepted

What happens to a Subtangle if it attaches to an invalid transaction?

Successfull merging of a subtangle and the main tangle: How to start a new offline subtangle? The case, that you have to reattach your whole subtangle occurs when you start your subtangle at a ...
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  • 4,459
3 votes

What happens to a Subtangle if it attaches to an invalid transaction?

When you have a large offline subtangle (which somebody already did the POW for); it is already attached to some (very old) transaction, which has hopefully confirmed until now (when starting an ...
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  • 7,254
3 votes
Accepted

Does the Tangle enforce a tip-selection algorithm?

The protocol does not enforce a particular tip selection algorithm, so every transaction-issuing network participant is free to choose whatever method they want. The IOTA reference implementation (IRI)...
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  • 1,663
3 votes
Accepted

Why is "getTransactionsToApprove" returning identical trunk & branch hashes

Strictly speaking : branch and trunk transaction can be the same. Let's think about transaction validating the genesis: there was only only one transaction on the tangle... so impossible to pick 2 ...
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  • 5,344
3 votes

Why are some transactions directly confirmed by two other transactions?

Not all nodes see the same state of the tangle at the same time. So it can be expected that two nodes pick the same tip (which might actually even not be a tip anymore) at the same time and issue ...
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  • 1,087
2 votes
Accepted

What are tips and what is the tip selection algorithm?

Tips in the context of iota (if they are not meaning small payments, as in tipbot) refer to transactions that have not been confirmed by other transactions. When you make a new transaction, you (or ...
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  • 7,254
2 votes
Accepted

Does the tip selection depend on how quickly the proof of work is done?

It is correct that tip selection generally favours newer transactions. So it is of benefit to finish your PoW quicker. But unless your computer takes a couple minutes, this should not have a huge ...
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  • 1,663
2 votes

Why does the tip-selection prefer new tips?

It must be obvious for everyone that attaching a new transaction to a transaction that was already validated is useless for the network. It must be obvious for everyone that a node should do it's ...
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  • 5,344
2 votes

Does the Tangle enforce a tip-selection algorithm?

The highlighted points of the tangle whitepaper are that first, you cannot enforce a selection strategy, and second, if you assume others are following monte carlo, then that is your best strategy to ...
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  • 316
2 votes

What happens to a Subtangle if it attaches to an invalid transaction?

Entire subtangle will be treated as invalid and won't be confirmed. That means you have to reattach all of the transactions.
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  • 201
2 votes

In IRI version 1.5.2, is the prevention of lazy tip selection a further entrenchment of the Coordinator?

I didn't check the code of IRI 1.5.2 in details, but as far as I understand, it seems that the changes in this version are really going in the same direction as the strategy of local modifiers in the ...
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  • 5,344
2 votes

Without the Coordinator, how will the network decide which double-spend succeeds?

Generally speaking, the double-spend which is directly and indirectly referenced by more transactions (i.e. has a larger cumulative weight) will most probably get confirmed. This is because more nodes ...
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  • 1,663
1 vote

How do transactions reference each other in the Tangle?

Each transaction has two fields, trunk transaction hash and branch transaction hash, which refer to 2 other transactions (contain the hash of the entirety of these two transaction). When building ...
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  • 7,254
1 vote

In IOTA can two transactions reference the same tips

There is no problem with that and it can't be completely avoided simply because of network latency. One tip can be selected in good faith by 2 different nodes at the same time. Note that lazy nodes ...
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  • 5,344
1 vote

Tip selection algorithm used for data transactions

I would question your first sentence. If you are not interested in getting your transaction confirmed, why do you want the transaction on the tangle anyway? One of the use cases of putting data on ...
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  • 7,254
1 vote
Accepted

How is the correct way to retrieve the two transactions that had been confirmed in order to create a transaction

As I'm new to Iota development I can not tell, if this is really the correct way to do it but I found the following works for me and the result looks correct and like what I expected it to look like: ...
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  • 131
1 vote

Are there entities that can submit transactions without having to approve a tip?

The IRI (Iota Reference Implementation) select the transactions to approve such that "selected transactions-to-approve are almost always tips". A tip is a transaction that isn't approved yet. This ...
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  • 5,344
1 vote

What's the incentive to use recommended tip selection algorithm for MAM transactions?

To be honest, I am not sure whether you can be that careless about whether your transactions confirm. There is no guarantee that unconfirmed transactions will (eventually) reach every node of the ...
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  • 7,254
1 vote

Does the Tangle enforce a tip-selection algorithm?

The IRI implements a random tip selection algorithm but you are free to modify it to select again and again the same transaction. It's what you do when you promote a transaction. Inundating the ...
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  • 5,344
1 vote

Priority spam tx?

Tip selection for approval does not look at the amounts at all, so it should not matter whether you do value transactions or zero-value transactions. however, I'd check that your node is synced (...
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  • 7,254
1 vote

API getTransactionsToApprove tip timeout

Transaction to approve are indeed called "tips". There is a tip selection algorithm doing the tip selection, and normally this algorithm should select transaction that are : recent probably not ...
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  • 5,344

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