Mike Ault's thoughts on various topics, Oracle related and not. Note: I reserve the right to delete comments that are not contributing to the overall theme of the BLOG or are insulting or demeaning to anyone. The posts on this blog are provided “as is” with no warranties and confer no rights. The opinions expressed on this site are mine and mine alone, and do not necessarily represent those of my employer.

Saturday, July 19, 2008

Atoms to Plowshears (Literally and figuratively)

I took a trip to Seattle, Washington (well, actually Bellevue) to attend PSOUG Oracle Days (Peugeot Sound Oracle Users Group) last week. The conference was fine, people seemed to get what they wanted from it (according to those I asked.) I wish more folks had come by the booth to ask about Texas Memory Systems SSD technology, but I guess you can’t have everything! I had about 20-30 folks in my presentation: “The New Tuning Universe of Oracle11g” and had some good questions and the audience was very interactive and showed interest.

After the conference I had some time to kill so I decided to visit Magnuson State Park. It wasn’t an arbitrary decision just selected at random from the Seattle area map, I had heard (and seen some pictures) of a sculpture there and decided to visit there if I could as a result. My first set of directions actually took me to the artist’s house, I didn’t stop in and say hi, but just backtracked and went to the park.

Partial Shot of Sculpture

In the picture shown above, if you are not sure what you are looking at, let me explain. From the 1950’s to the current date the USA has been building and using Nuclear Submarines, starting with the USS Nautilus, SSN 571 commissioned in 1954. Both search and destroy (fast attack) and stealth missile deployment (Ballistic Missiles) submarines utilize stern planes and sail planes (the “sail” is what landlubbers would call the conning tower.) The sail planes are also called the dive planes as they are used to cause the submarine to dive and surface when it is neutrally buoyant.
The sail planes have to be particularly ridged and strong as they needed to also withstand the incredible forces generated when a submarine is forced to break through the ice in polar regions, while still being relatively light weight. This strong but light structure for the sail planes was achieved by making them hollow and filling them with special high density foam. The high density foam makes them very difficult to melt down, so when the submarines are decommissioned and scrapped, the sail planes are usually set aside.
In 1998 John T. Young, a Seattle artist, asked the government for any stainless steel scraps he could use for doing sculptures and they gave him the sail planes from several decommissioned and scrapped submarines, he used them to create 2 sculptures, one in Seattle and one in Miami, the submarines used were:

Seattle Fins: SSN 669 Seahorse, SSBN 641 Simon Bolivar, SSN 652 Puffer, SSN 615 Gato, SSBN 620 John Adams, SSN 595 Plunger, SSN 638 Whale, SSN 667 Bergall, SSN 673 Flying Fish, SSN 597 Tullibee, SSN 650 Pargo, SSN 662 Gurnard.

Miami Fins: Sea Devil SSN 664, Pogy SSN 647, Sand Lance SSN 660, Pintado SSN 672, Trepang SSN 674, Billfish SSN 676, Archerfish SSN 678, Tunny SSN 682, Von Steuben SSBN 632, Sculpin SSN 590, Cavalla SSN 684.

I served on two nuclear submarines during the period 1976-1979, the USS John Adams, SSBN 620 and the USS Bergall, SSN 667, so you can see my interest in the Seattle sculpture. The SSBN on the Adams number means she was a ballistic missile boat, we carried up to 16 Poseidon missiles with MIRV warheads (multiple independent re-entry vehicle, meaning each missile of the Poseidon class could hit multiple targets) with the nuclear capability that exceeded the explosive power of all the munitions used in WWII. All this was used to carry out the MAD (mutually assured destruction) doctrine between the USA, USSR and at times Communist (Red) China, although the main targets were predominantly in the USSR. The SSN means the Bergall was a fast attack submarine used to hunt and kill other ships, including hostile submarines.

The MAD concept was that the SSBN type submarines, being undetectable, would be unstoppable launch platforms that would be used to respond to any nuclear aggression from anywhere in the world. Thus assuring we could utterly destroy Russian civilization should they launch a first attack that succeeded in taking out our land based missile systems. The Russians spent a great deal of time, money and resources trying to find ways to beat the SSBN submarines, in no small part they were one of the key technologies that kept the Russians and Chinese from launching a first strike during the worst part of the cold war.

ComSubLAnt (Commander Submarine Atlantic) could communicate with us using radio and LFT (Low Frequency Transmissions.) They kept the encrypted traffic going 24X7 replacing any actual command traffic with 15 word family grams, news and other items to not allow the Russians the ability to sense something was happening by seeing increased communications traffic. Each sailor was only allowed a limited number of family grams per patrol, no reverse communication, from the sailors back to the families was allowed. A patrol lasted 3 months with most of that spent underwater on patrol and the balance in such sun-fun spots as Holy Loch, Scotland repairing what the other crew broke on their patrol. The SSBNs had two crews, the Golds and Blues, I was on the gold crew. You usually spent about 70-80 days underwater with no fresh air, no outside views and no females! Your biggest enemies where boredom and doing qualifications, you didn’t think about the hundreds of pounds per square inch of pressure that were striving to snuff out your life every second of every day while you were on patrol or you would go mad.

We were the warriors of the cold war. The cold war was officially over (at least most felt it was) when the Berlin wall was taken down in 1989, the submarine fleet was as much responsible for that as any president. We were away 3 months out of every 6 from our families, for these patrols, I did 5 patrols and a DASO run for a total of 18 months out of the 33 I spent on the Adams. At just about any time during those 18 months a worn seal, a broken valve, a busted pipe could have killed us all, as it did for the sailors on the two nuclear submarines that didn’t come back, the USS Thresher, SSN 593 and the USS Scorpion, SSN 589. Believe me, listening to the pings and squeals as we went to test and one time to crush depth was a bit unnerving when you realized how much pressure it took to do that to several inches of stainless steel pressure hull. The Russians lost several submarines during that time as well and now most of their fleet lies in ruins silently rusting away at the piers in Vladivostok and other Russian ports.

As I stood there and placed my hand against the only surviving part of the submarine that had guarded my (and your) life both directly when I was aboard her and indirectly through the MAD concept when I wasn’t I couldn’t help but feel a bit nostalgic and melancholy that such a fine ship met such an ignoble end as becoming feed stock for John Deere tractors except for one sail plane in this sculpture garden. Of course the transition from a ship of war to farm implements maybe has greater cosmic import that I realize. The Bergall had both of her sail planes here, but since I only spent a few months and never went to sea on her, I didn’t feel the connection I did with the Adams.

As I wandered the sculpture garden taking pictures I heard and watched a group of children playing on a nearby hill. Later from that same hill I watched them walk down through the sculpture garden toward the beach and right past the last intact piece of the USS John Adams. I wondered if any of them truly understood what that piece of steel really meant? Of course maybe it’s true purpose was so that they never again would have to live under the threat of nuclear annihilation of the entire planet. I hope someone explains it to them, so that the meaning is not forgotten.

The Author beside the USS John Adams SSBN 620 Sail Plane

Wednesday, July 02, 2008

Lies, Damn Lies and SSD Technology

As I am now employed by a company that manufactures solid state drives for use by databases and other applications that require high speed, high bandwidth access to data. I have taken to reading articles, blogs and other sources whenever I see they discuss SSD related topics. Through this practice I have found there are woefully uninformed folks making very many untrue statements about solid state drive technology.

Let’s look at some of the highlights:

1. Solid state drive technology is very expensive
2. Solid state devices are best when directly attached to the internal bus architecture
3. Solid state drives will only be niche players
4. You can get the same IO rate from disks as from SSD

First, the myth that solid state drives are expensive was, like many myths involving Oracle and computers, true at one time, however, times change. The huge leap in demand for flash memory with the advent of I-pods, digital cameras and video recorders has created a memory glut. You can get a 4 gigabyte flash memory stick or card for under a hundred dollars for your camera or other flash device. In fact memory prices promise to plunge even farther as mass production techniques and miniaturization technology improves. The cost for a gigabyte of enterprise class disk storage is around $84 at last count, for the most current version of the Texas Memory System RAMSAN SSD technology, using flash memory and regular memory, the cost is around $100 per gigabyte, with further decreases in memory costs, RAMSAN SSD prices will fall even further.

Second, in a recent article a producer of both disk and solid state technology seemed to indicate it works best when hooked directly into the internal bus for the computer and really wasn’t efficient when attached as a SAN would be attached. I am not sure where he is getting his information (other than his company is trying to shoe-horn solid state drive technology into their existing SAN infrastructure) but it has been my experience that rarely if ever do users flood the fibre channels, they may overload a couple of the disk drives, but generally the SAN connections are not the source of the bottleneck when it comes to SAN technology. Using standard fibre channel connections and standard host bus adapters Texas memory Systems achieves over 400,000 IOPS from a single 4U RAMSAN SSD. To get the equivalent IOPS using regular disk technology you would need over 6000 or more individual disk drives, the racks to hold them and the controllers to control them, not to mention the air conditioning and electrical power needed for that many disks.

Next, solid state drives will only be niche players, this is a ridiculous statement. Most clients of RAMSAN SSD technology use them just as they would disk arrays. The RAMSAN SSD technology will replace disks as we know it in the near future and disks will be relegated to second tier storage and backup duties, replacing tapes. Many experts are talking of the tier 0 level of storage and specifically mentioning SSD when they do so. When you can place a single 4U sized RAMSAN SSD into your system and replace literally hundreds or thousands of disks the idea that they will only be niche devices is foolish. This is especially true when you consider the decreasing costs, the ease of administration and the performance gains that you get when SSD technology is properly deployed.

Finally, the myth that with disks you can get the same IOPS as with SSD. Yes, you can, however, you would need X/(IOPS/disk) number of disks where X is the desired IOPS to achieve it, double that number for RAID10 or RAID01. Even high speed 15K drives can only deliver around 100 to 130 IOPS per second of random reads due to the mechanical nature of disk drives, as the late Scotty on the Federation Starship Enterprise used to say (about every other episode): “Ya cannot change the laws of physics.” Disks, without prohibitive cooling technologies, cannot exceed certain maximum rotational speeds, read heads, mounted on mechanical arms can only move so fast and the magnetic traces can only be packed so close on the disk surface. To get 400,000 IOPS you would need at least (400,000/130)*2= 6153 drives in a RAID10 array. At 18 drives per tray that is 341 trays of disk drives at 8 trays per rack that is almost 43 racks needed to hold the drives. Now, even with the largest caches available you still require anywhere from a millisecond to several (up to 5 with minimal loads, higher with large loads or more than single block reads) milliseconds to do each IO, this latency will always be there in a disk based system, the latency on SSD based systems such as RAMSAN are in the hundreds of nanoseconds range (fractional milliseconds).

So, what have we determined? We have found that SSD technology is comparable in cost with enterprise level disk systems and will soon beat the cost of enterprise level disk systems. We have also seen that SSD technology when properly designed and implemented (not shoe-horned into a disk-based SAN) will fulfill the promise of fibre technology and allow use of the bandwidth currently squandered by disk technology. We have also seen that far from being a niche technology, SSD is becoming the tier 0 storage for many companies and will soon supplant disks as the primary storage medium in many applications. Finally, while it is possible to achieve the same level of IOPS using disk technology that SSD technology provides, it would be cost prohibitive to do so, and, even if you did achieve the same level of IOPS, each IO would still be subject to the same disk based latencies.

I am not afraid to say it: SSD technology is here, it is ready for prime time and it is only a matter of time before disks are relegated to second tier storage. Disks are dead, they just don’t know it yet.