Hi joe, I moved the content and providence repositories off to two new disks, but it seems like the vast majority of the writes are still occurring on the disk where the flowfile and database repositories are. I note they don't appear to be able to be split across disks in the same way?
On Fri, 14 Sep 2018 at 12:37, Joe Witt <joe.w...@gmail.com> wrote: > if they are physically seperate the diff should be quite noticable. > > On Thu, Sep 13, 2018, 7:36 PM Phil H <gippyp...@gmail.com> wrote: > > > Potentially. We're looking to see how the multiple disks help before > > committing to spending money on new hardware :) > > > > On Fri, 14 Sep 2018 at 10:48, Joe Witt <joe.w...@gmail.com> wrote: > > > > > phil, > > > > > > as you add dirs it will just start using them. if you want to no > longer > > > use the current dir it might be more involved. > > > > > > does that help? > > > > > > thanks > > > > > > On Thu, Sep 13, 2018, 4:36 PM Phil H <gippyp...@gmail.com> wrote: > > > > > > > Follow up question - how do I transition to this new structure? > Should > > I > > > > shut down NiFi and move the contents of the legacy single directories > > > into > > > > one of the new ones? For example: > > > > > > > > mv /usr/nifi/content_repository > > > > /nifi/repos/content-1 > > > > > > > > TIA > > > > Phil > > > > > > > > > > > > On Wed, 12 Sep 2018 at 06:15, Mark Payne <marka...@hotmail.com> > wrote: > > > > > > > > > Phil, > > > > > > > > > > For the content repository, you can configure the directory by > > changing > > > > > the value of > > > > > the "nifi.content.repository.directory.default" property in > > > > > nifi.properties. The suffix here, > > > > > "default" is the name of this "container". You can have multiple > > > > > containers by adding extra > > > > > properties. So, for example, you could set: > > > > > > > > > > nifi.content.repository.directory.content1= > > > > > /nifi/repos/content-1 > > > > > > > > > > nifi.content.repository.directory.content2=/nifi/repos/content-2 > > > > > nifi.content.repository.directory.content3=/nifi/repos/content-3 > > > > > nifi.content.repository.directory.content4=/nifi/repos/content-4 > > > > > > > > > > Similarly, the Provenance Repo property is named > > > > > "nifi.provenance.repository.directory.default" > > > > > and can have any number of "containers": > > > > > > > > > > nifi.provenance.repository.directory.prov1=/nifi/repos/prov-1 > > > > > nifi.provenance.repository.directory.prov2=/nifi/repos/prov-2 > > > > > nifi.provenance.repository.directory.prov3=/nifi/repos/prov-3 > > > > > nifi.provenance.repository.directory.prov4=/nifi/repos/prov-4 > > > > > > > > > > When NiFi writes to these, it does a Round Robin so that if you're > > > > writing > > > > > to 4 Flow Files' > > > > > content simultaneously with different threads, you're able to get > the > > > > full > > > > > throughput of each > > > > > disk. (So if you have 4 disks for your content repo, each capable > of > > > > > writing 100 MB/sec, then > > > > > your effective write rate to the content repo is 400 MB/sec). > Similar > > > > with > > > > > Provenance Repository. > > > > > > > > > > Doing this also will allow you to hold a larger 'archive' of > content > > > and > > > > > provenance data, because > > > > > it will span the archive across all of the listed directories, as > > well. > > > > > > > > > > Thanks > > > > > -Mark > > > > > > > > > > > > > > > > > > > > > On Sep 11, 2018, at 3:35 PM, Phil H <gippyp...@gmail.com> wrote: > > > > > > > > > > > > Thanks Mark, this is great advice. > > > > > > > > > > > > Disk access is certainly an issue with the current set up. I will > > > > > certainly > > > > > > shoot for NVMe disks in the build. How does NiFi get configured > to > > > span > > > > > > it's repositories across multiple physical disks? > > > > > > > > > > > > Thanks, > > > > > > Phil > > > > > > > > > > > > On Wed, 12 Sep 2018 at 01:32, Mark Payne <marka...@hotmail.com> > > > wrote: > > > > > > > > > > > >> Phil, > > > > > >> > > > > > >> As Sivaprasanna mentioned, your bottleneck will certainly depend > > on > > > > your > > > > > >> flow. > > > > > >> There's nothing inherent about NiFi or the JVM, AFAIK that would > > > limit > > > > > >> you. I've > > > > > >> seen NiFi run on VM's containing 4-8 cores, and I've seen it run > > on > > > > bare > > > > > >> metal > > > > > >> on servers containing 96+ cores. Most often, I see people with a > > lot > > > > of > > > > > >> CPU cores > > > > > >> but insufficient disk, so if you're running several cores ensure > > > that > > > > > >> you're using > > > > > >> SSD's / NVMe's or enough spinning disks to accommodate the flow. > > > NiFi > > > > > does > > > > > >> a good > > > > > >> job of spanning the content and FlowFile repositories across > > > multiple > > > > > >> disks to take > > > > > >> full advantage of the hardware, and scales the CPU vertically by > > way > > > > of > > > > > >> multiple > > > > > >> Processors and multiple concurrent tasks (threads) on a given > > > > Processor. > > > > > >> > > > > > >> It really comes down to what you're doing in your flow, though. > If > > > > > you've > > > > > >> got 96 cores and > > > > > >> you're trying to perform 5 dozen transformations against a large > > > > number > > > > > of > > > > > >> FlowFiles > > > > > >> but have only a single spinning disk, then those 96 cores will > > > likely > > > > go > > > > > >> to waste, because > > > > > >> your disk will bottleneck you. > > > > > >> > > > > > >> Likewise, if you have 10 SSD's and only 8 cores you're likely > > going > > > to > > > > > >> waste a lot of > > > > > >> disk because you won't have the CPU needed to reach the disks' > > full > > > > > >> potential. > > > > > >> So you'll need to strike the correct balance for your use > > case.Since > > > > you > > > > > >> have the > > > > > >> flow running right now, I would recommend looking at things like > > > `top` > > > > > and > > > > > >> `iostat` in order > > > > > >> to understand if you're reaching your limit on CPU, disk, etc. > > > > > >> > > > > > >> As far as RAM is concerned, NiFI typically only needs 4-8 GB of > > ram > > > > for > > > > > >> the heap. However, > > > > > >> more RAM means that your operating system can make better use of > > > disk > > > > > >> caching, which > > > > > >> can certainly speed things up, especially if you're reading the > > > > content > > > > > >> several times for > > > > > >> each FlowFile. > > > > > >> > > > > > >> Does this help at all? > > > > > >> > > > > > >> Thanks > > > > > >> -Mark > > > > > >> > > > > > >> > > > > > >>> On Sep 10, 2018, at 6:05 AM, Phil H <gippyp...@gmail.com> > wrote: > > > > > >>> > > > > > >>> Thanks for that. Sorry I should have been more specific - we > > have a > > > > > flow > > > > > >>> running already on non-dedicated hardware. Looking to identify > > any > > > > > >>> limitations in NiFi/JVM that would limit how much parallelism > it > > > can > > > > > take > > > > > >>> advantage of > > > > > >>> > > > > > >>> On Mon, 10 Sep 2018 at 14:32, Sivaprasanna < > > > > sivaprasanna...@gmail.com> > > > > > >>> wrote: > > > > > >>> > > > > > >>>> Phil, > > > > > >>>> > > > > > >>>> The hardware requirements are driven by the nature of the > > dataflow > > > > you > > > > > >> are > > > > > >>>> developing. If you're looking to play around with NiFi and > gain > > > some > > > > > >>>> hands-on experience, go for a 4 core 8GB RAM i.e. any modern > > > > > >>>> laptops/computer would do the job. In my case, where I'm > having > > > 100s > > > > > of > > > > > >>>> dataflows, I have it clustered with 3 nodes. Each having 16GB > > RAM > > > > and > > > > > >> 4(8) > > > > > >>>> cores. I went with SSDs of smaller size because my flows are > > > > involved > > > > > in > > > > > >>>> writing to object stores like Google Cloud Storage, Azure Blob > > and > > > > > >> Amazon > > > > > >>>> S3 and NoSQL DBs. Hope this helps. > > > > > >>>> > > > > > >>>> - > > > > > >>>> Sivaprasanna > > > > > >>>> > > > > > >>>> On Mon, Sep 10, 2018 at 4:09 AM Phil H <gippyp...@gmail.com> > > > wrote: > > > > > >>>> > > > > > >>>>> Hi all, > > > > > >>>>> > > > > > >>>>> I've been asked to spec some hardware for a NiFi > installation. > > > Does > > > > > >>>> anyone > > > > > >>>>> have any advice? My gut feel is lots of processor cores and > > RAM, > > > > with > > > > > >>>> less > > > > > >>>>> emphasis on storage (small fast disks). Are there any > > limitations > > > > on > > > > > >> how > > > > > >>>>> many cores the JRE/NiFi can actually make use of, or any > other > > > > > >>>>> considerations like that I should be aware of? > > > > > >>>>> > > > > > >>>>> Most likely will be pairs of servers in a cluster, but again > > any > > > > > advice > > > > > >>>> to > > > > > >>>>> the contrary would be appreciated. > > > > > >>>>> > > > > > >>>>> Cheers, > > > > > >>>>> Phil > > > > > >>>>> > > > > > >>>> > > > > > >> > > > > > >> > > > > > > > > > > > > > > > > > > > >
