Hello, Maksim! I am currently working on a review notes from Alexey Plekhanov, will let you know when I finish.
пн, 28 сент. 2020 г. в 11:04, Maksim Stepachev <maksim.stepac...@gmail.com>: > > Hi, Pavel. > > As I see, the ticket [https://issues.apache.org/jira/browse/IGNITE-12843] > is "PATCH AVAILABLE". Is this ticket finished? > > чт, 13 авг. 2020 г. в 13:49, Pavel Pereslegin <xxt...@gmail.com>: > > > Hello all. > > > > I'm working on TDE cache group key rotation [1] and I have a couple of > > questions about partition re-encryption. > > > > As described in the wiki [2], the process of re-encryption at the > > moment consists of sequentially marking memory pages as dirty, this > > process looks not resource-intensive. > > Do you think it is necessary to do this in a multithreaded mode or > > single thread is enough? > > (We started testing re-encryption on dedicated servers (Xeon E5-2680 > > 2.4Ghz, SSD Huawei ES3600P 3.2TB, ThrottlingPolicy = > > CHECKPOINT_BUFFER_ONLY) with no speed limit and no load, as a result, > > single-threaded encryption loaded disk within 30%. At the same time, > > the total re-encryption speed was around 60 MB/s, which allows one > > node to re-encrypt 1 TB of data in about 5 hours, and it seems that > > this performance is enough.) > > > > The second question is about the approach to storing the re-encryption > > status. > > At the moment, the re-encryption status includes two parameters - the > > total number of pages in the partition at the time of the start of > > re-encryption (int) and the index of the last re-encrypted page (int). > > These 8 bytes are stored in the metapage on the checkpoint (which > > ensures that if the checkpoint does not happen, we will continue the > > process from the last page written to disk). > > However, if multithread partition scanning does not make sense, then > > it seems that it is possible to change the implementation and don't > > change the metapage structure. Store only the "pointer" of the > > partition (and the cache group) in the metastore and scan in strict > > order. > > The approach with storing the status in the metapage of the partition > > seems to me more flexible, stable and has a number of advantages over > > the "pointer" approach: > > 1. Since we saving the total number of pages at the re-encryption > > startup - we will not scan extra pages that may be added to the > > partition later. > > 2. We can move partitions between nodes and re-encryption should > > continue from a certain point on the new node. > > 3. If a partition is (re)created during cache group re-encryption, it > > will not be re-encrypted (since its re-encryption status will be reset > > and all data is encrypted with the latest encryption key after > > (re)creation. > > > > Do you think single-threaded mode is enough? > > Is it better to keep the re-encryption status in the metapage or store > > the "pointer" in the metastore? > > > > [1] https://issues.apache.org/jira/browse/IGNITE-12843 > > [2] > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=95652384#TDE.Phase3.Cachekeyrotation.-Backgroundre-encryption > > > > пт, 31 июл. 2020 г. в 11:09, Pavel Pereslegin <xxt...@gmail.com>: > > > > > > Hello, > > > > > > I'll expand the answer a bit about calculating CRC, the problem is not > > > that it is calculated twice, but that now for encrypted pages, > > > EncryptedFileIO checks physical integrity, and FilePageStore checks > > > the correctness of the encryption key, but from my point of view, it > > > should be vice versa - the lower (delegated) FileIO should check the > > > physical integrity and EncryptedFileIO should check the correctness of > > > the encryption key. > > > > > > пт, 31 июл. 2020 г. в 10:40, Pavel Pereslegin <xxt...@gmail.com>: > > > > > > > > Hello, > > > > > > > > > 10. Question - CRC is read in two places encryptionFileIO and > > > > > filePageStore - what should we do with this? > > > > > > > > We need to calculate the CRC of encrypted data, because we may be > > > > using the wrong encryption key to decrypt data, in which case we will > > > > not understand if the physical integrity is violated or the wrong > > > > encryption key is used. > > > > > > > > > 9. Question - How do we optimize when we can check that this page is > > > > > already encrypted by parallel loading? Maybe we should do this in > > Phase 4? > > > > > > > > To do this, we need to store the encryption key ID in memory (at > > > > least), but this is not easy to do right now without breaking binary > > > > compatibility. > > > > > > > > > 7. Question -the current implementation does not use the throttling > > that > > > > > is implemented in PDS. Users should set the throughput such as 5 MB > > per > > > > > second, but not the timeout, packet size, or stream size. > > > > > > > > I've added a simple rate limiter for this. > > > > > > > > > 8. Question - why we add a lot of system properties? > > > > >> Can you, please, list system properties that should be moved to the > > configuration? > > > > > > > > It's about the background re-encryption properties, for now, it is: > > > > - re-encryption speed limit (in megabytes per second) > > > > - threads count used for re-encryption > > > > - count of pages in batch, processed under checkpoint lock > > > > - flag to completely disable background re-encryption > > > > > > > > > 11. We should remember about complicated test scenarios with failover > > > > > > > > PR contains tests for re-encryption (and key rotation) on unstable > > > > topology (with baseline change and without it). I'll expand them if I > > > > missed some cases. > > > > > > > > > 13. Will re-encryption continue after the cluster is completely > > stopped? > > > > > > > > Yes, as I mentioned earlier, we save the re-encryption status in the > > > > meta page of each re-encrypted partition and trigger re-encryption on > > > > node startup if needed (more detailed description on the wiki). > > > > > > > > Thanks a lot for your comments, I am still working on PR and expanding > > > > wiki documentation. I'll let you know when it will be ready for the > > > > review. > > > > > > > > вт, 28 июл. 2020 г. в 19:14, Alexey Goncharuk < > > alexey.goncha...@gmail.com>: > > > > > > > > > > Hello Nikolay, > > > > > > > > > > > > > > > > > 10. Question - CRC is read in two places encryptionFileIO and > > > > > > filePageStore - what should we do with this? > > > > > > > > > > > > filePageStore checks CRC of the encrypted page. This required to > > confirm > > > > > > the page not corrupted on the disk. > > > > > > encryptionFileIO checks CRC of the decrypted page(CRC itself > > stored in the > > > > > > encrypted data). > > > > > > This required to be sure the decrypted page contains correct data > > and not > > > > > > replaced with some malicious content. > > > > > > > > > > > > > > > > I still do not see why we need CRC twice, can you please elaborate > > on this > > > > > statement? If an attacker is able to replace the contents of an > > encrypted > > > > > page, it means that they have access to the encryption key. What will > > > > > prevent them from calculating the CRC of malicious content and then > > > > > encrypting it? > >
