Google Cloud Bigtable Durability/Availability Guarantees -

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i google provide guidelines on durability , availability guarantees provided cloud bigtable service.

here understanding far:

  • the fact minimum cluster requires 3 nodes suggests that, @ least within zone, data highly durable , replicated 3 nodes.

  • however, this answer googler states "cloud bigtable doesn’t replicate data" — directly contradicting quote on cloud bigtable homepage claims "is built replicated storage strategy". it? replicated or not? , if so, how many copies kept?

  • the fact clusters can set within particular zone suggests availability of cluster tied directly availability of zone. if want have highly available bigtable-based data storage, best practice set independent clusters across multiple zones , handle synchronisation of writes across clusters myself?

there no information on whether bigtable clusters across zones independent or not. if set clusters across multiple zones, , 1 zone goes down, expect clusters in other zones carry on working? or there underlying single point of failure impact clusters across zones?

compared app engine datastore specific these details, cloud bigtable documentation rather lacking — or, @ least, i've not managed find page goes detail on these aspects.

the cloud bigtable docs vague on other aspects, e.g. on matter of size limits values, the documentation states individual values should stay below "~10 mb per cell". on earth "~10 mb" mean?! can hardcode limit of 10mb , expect work or change day day dependent on unknown factors?

anyway, apologies if sound agitated. genuinely use bigtable service. i, presumably many others, need understand durability/availability aspects of before being able invest in it. thank you.

on replication: answer referenced referring replication of data across bigtable clusters, not supported @ time. (for example, bigtable cluster in united states replicating writes second cluster in europe)

this concept separate replication of data within bigtable cluster, analogous replication in hdfs, product absolutely today.

on availability: yes, availability of bigtable cluster tied availability of google cloud zone.

on independence: yes, cloud bigtable clusters independent across zones. outage in 1 zone should not impact availability of other zones.

on data per cell: not reject writes >10mb per cell, have set guideline getting optimal performance.


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