6 ms·

You can run most applications on a single server - IBM S/390 big iron has very high reliability, redundancy and I/O bandwidth.

catlifeonmars 4y ago
Yes but it’s literally a single point of failure. You probably want at least two servers in separate physical locations. Also how do you do deployments without interruption of service on a single server?
- SgtBastard 4y ago
  Blue/green deployments and request draining like with any other deployment topology.
- ElectricalUnion 4y ago
  > it’s literally a single point of failure. Those machines are made very redundant. All components in a Parallel Sysplex configuration can operate in redundant mode. Redundant power. Redundant central processor complex. Redundant multichip module (what would be a chipset on microcomputer platforms). Redundant RAM Memory. Redundant Storage. Redundant internal interconnects. Redundant network adapters. That's why corporations that require high availability to not get sued for millions/billions use them.
  - catlifeonmars 4y ago
    Redundant physical location. That means different power dependencies and different cities.
    - ElectricalUnion 4y ago
      > Redundant physical location. That means different power dependencies and different cities. Geographically Dispersed Parallel Sysplex.
vbezhenar 4y ago
What if I have $500/month to spend and still need high reliability and redundancy?
- JAlexoid 4y ago
  That's a budget for a local crafts store website hosting, not "high availability" system
  - KronisLV 4y ago
    > That's a budget for a local crafts store website hosting, not "high availability" system I'm not sure about that: you could still put something together within that budget, say, a few different VPSes across Hetzner and Contabo (or different regions within the same provider's offerings), with some circuit breaking and load balancing between those. Probably either a managed database offering, or a cluster of DBs running on similar VPSes. Of course, this might mean that you have 1-3 instances of a service instead of 10-30, but as long as availability is the goal and not necessarily throughput, that can go pretty far.
    - JAlexoid 4y ago
      If you're a amateur something, that just does it for fun - sure Otherwise what you have is a budget that is lower than the possible implications of temporary downtime. That doesn't make sense in the real world.
      - KronisLV 4y ago
        > If you're a amateur something, that just does it for fun - sure sed "s/amateur/comparatively poor, from a third world country, without VC money, or have cheap labor/g" Not everyone can afford advanced tools or platforms, or even using something like AWS/Azure/GCP. Some of those can indeed be amateur use cases (e.g. side project or bootstrapped SaaS), others simply stretching your money for any number of considerations (e.g. non profit, limited budget etc.), but it's definitely possible. In some countries it probably makes more sense to just build your own solution, as long as you're not doing anything too advanced. 500 USD a month would get you approximately the following resources (taxes vary) on the aforementioned platforms: Contabo Nodes: 15 to 83 (depending on configuration) CPU: 150 to 332 cores RAM: 664 to 900 GB SSD: 4150 to 6000 GB Hetzner Nodes: 7 to 110 (depending on configuration) CPU: 86 to 192 cores RAM: 192 to 384 GB SSD: 2200 to 4800 GB (this includes regular VPS packages, not storage optimized ones, or dedicated hosting etc.) I'm not sure about you, but in my experience that could be enough for some pretty decent systems, albeit some storage heavy workloads would need the storage packages instead of the regular VPS ones. It's mostly a matter of picking a suitable topology and working towards your goals. > Otherwise what you have is a budget that is lower than the possible implications of temporary downtime. That doesn't make sense in the real world. This (depending on the circumstances) does sound like a good point! Maybe "the real world" isn't the best wording, though, and choosing "enterprise settings" or anything along those lines would be more suitable.

catlifeonmars 4y ago

Yes but it’s literally a single point of failure. You probably want at least two servers in separate physical locations. Also how do you do deployments without interruption of service on a single server?

SgtBastard 4y ago
Blue/green deployments and request draining like with any other deployment topology.
ElectricalUnion 4y ago
> it’s literally a single point of failure. Those machines are made very redundant. All components in a Parallel Sysplex configuration can operate in redundant mode. Redundant power. Redundant central processor complex. Redundant multichip module (what would be a chipset on microcomputer platforms). Redundant RAM Memory. Redundant Storage. Redundant internal interconnects. Redundant network adapters. That's why corporations that require high availability to not get sued for millions/billions use them.
- catlifeonmars 4y ago
  Redundant physical location. That means different power dependencies and different cities.
  - ElectricalUnion 4y ago
    > Redundant physical location. That means different power dependencies and different cities. Geographically Dispersed Parallel Sysplex.

vbezhenar 4y ago

What if I have $500/month to spend and still need high reliability and redundancy?

JAlexoid 4y ago
That's a budget for a local crafts store website hosting, not "high availability" system
- KronisLV 4y ago
  > That's a budget for a local crafts store website hosting, not "high availability" system I'm not sure about that: you could still put something together within that budget, say, a few different VPSes across Hetzner and Contabo (or different regions within the same provider's offerings), with some circuit breaking and load balancing between those. Probably either a managed database offering, or a cluster of DBs running on similar VPSes. Of course, this might mean that you have 1-3 instances of a service instead of 10-30, but as long as availability is the goal and not necessarily throughput, that can go pretty far.
  - JAlexoid 4y ago
    If you're a amateur something, that just does it for fun - sure Otherwise what you have is a budget that is lower than the possible implications of temporary downtime. That doesn't make sense in the real world.
    - KronisLV 4y ago
      > If you're a amateur something, that just does it for fun - sure sed "s/amateur/comparatively poor, from a third world country, without VC money, or have cheap labor/g" Not everyone can afford advanced tools or platforms, or even using something like AWS/Azure/GCP. Some of those can indeed be amateur use cases (e.g. side project or bootstrapped SaaS), others simply stretching your money for any number of considerations (e.g. non profit, limited budget etc.), but it's definitely possible. In some countries it probably makes more sense to just build your own solution, as long as you're not doing anything too advanced. 500 USD a month would get you approximately the following resources (taxes vary) on the aforementioned platforms: Contabo Nodes: 15 to 83 (depending on configuration) CPU: 150 to 332 cores RAM: 664 to 900 GB SSD: 4150 to 6000 GB Hetzner Nodes: 7 to 110 (depending on configuration) CPU: 86 to 192 cores RAM: 192 to 384 GB SSD: 2200 to 4800 GB (this includes regular VPS packages, not storage optimized ones, or dedicated hosting etc.) I'm not sure about you, but in my experience that could be enough for some pretty decent systems, albeit some storage heavy workloads would need the storage packages instead of the regular VPS ones. It's mostly a matter of picking a suitable topology and working towards your goals. > Otherwise what you have is a budget that is lower than the possible implications of temporary downtime. That doesn't make sense in the real world. This (depending on the circumstances) does sound like a good point! Maybe "the real world" isn't the best wording, though, and choosing "enterprise settings" or anything along those lines would be more suitable.