Online Eviction Forms: Fill & Download for Free

At Quora, the infrastructure team maintains a variety of online datastores. The data-platform team maintains offline datastores for our data pipeline use cases (e.g. HDFS, Redshift, etc.); for more information on those, see Angela’s answer to “What does the Data Platform team do at Quora?”. Here, I'll focus on the datastores we use to serve online web queries.For online data, we have two main categories of datastores: caching datastores and ground-truth datastores. Caching datastores are extremely fast. However, data stored in caches could be lost due to eviction or failures, and they only support very basic key-value lookups. Ground-truth datastores are relatively slower, but they provide reliability guarantees and more flexible, powerful APIs.Caching datastoresPycachePycache is an in-memory key-value store we developed in-house. (Read Martin Michelsen's answer to What is Quora's pycache? to learn more!) The contents are stored in a shared memory map used by all Python processes running on the same box, and fetching data is very fast because no network overhead is required (and in most cases, no system calls are even made). The data in Pycache is backed by a commit log in MySQL, and is never evicted.However, the capacity of Pycache is bounded by the smallest available memory of the EC2 instances we use, so we only store small objects which have small key spaces that need frequent and fast lookups. For example, Pycache stores all Quora employees' user IDs, translated strings for UIs for other languages, topics with special flags, etc.MemcacheMemcache is also an in-memory key-value store for caching small objects. We run it in multiple distributed clusters with Amazon EC2's memory optimized instances. Data is sharded to each instance using a consistent hashing algorithm, so it's easy and minimally disruptive to add capacity to the cluster. Memcache also supports features like atomic increments / decrements / appends and cas (check-and-set), which are not supported by Pycache.In our production environment, the p90 latency for Memcache is around 0.3 ms for get/get_multi operations. Memcache is used across our product to help increase speed and reduce load to other ground-truth datastores. If you’re interested in learning more, read Siyuan Fu (富思源)'s answer to How does Quora monitor its Memcached cluster?Redis cacheWe have a sharded Redis cluster (relatively smaller than our main Memcache cluster) that also serves as an in-memory caching system. We use Redis to resolve scalability issues where we used to store lists and sets in Memcache. When updating a large list or set in Memcache, we would have to recompute (or at least retrieve) the entire list, and send the entire updated list back to the server. For example, updating the list of people who have upvoted your answer each time you get a new upvote.Redis has native support for data structures. Using Redis as an LRU cache makes it possible to easily update an element in a large list (we use sorted sets for this), which improves the cache hit rate and reduces load on ground-truth datastores. However, we'll need to make sure that we use the right query pattern - for example, getting an entire sorted set is expensive (an O(N) operation), so we only use Redis for lists where we often do size or membership checks (both are constant-time operations).Ground-truth datastoresMySQLMySQL is a relational database and our primary ground-truth datastore. We store data in MySQL if the data makes more sense in a relational database than in a NoSQL database (for example, if the access patterns require many indexes), or if complex queries are required upon the data. At Quora, the infrastructure team maintains a shared MySQL cluster used by all product teams. Because it's shared across the company, the infrastructure team also build and maintains tools and monitoring around it to prevent inefficient queries from affecting other parts of the product. Follow the question How does Quora monitor MySQL clusters? if you want to learn more details.In general, MySQL is suitable for tables with a large number of rows (up to a billion or so) and a small, fixed number of columns. It supports complex queries (joins and aggregations) and secondary indexes. The p90 latency for our MySQL clusters is slightly > 1 ms; most of our MySQL instances are EC2's i3 class.Unlike caching datastores, data stored in ground-truth datastores will never be evicted or lost. We back up all ground-truth datastores (MySQL, HBase, and Redis) to multiple offline storage systems regularly, and we verify the integrity of these snapshots regularly as well. We could restore all ground-truth datastores from these backups in case of catastrophic failure of all of our running EC2 instances. To learn more about how we back up, follow the question What is Quora's backup strategy for its databases?HBaseHBase is a horizontally scalable NoSQL database. Compared with MySQL, HBase tables perform well with a very large number of rows (billions) and millions of columns. HBase supports more parallelism on each table than MySQL, and can automatically expire historical versions of data. At Quora, there are multiple HBase clusters running in parallel, serving as the main ground-truth datastore for different services.HBase supports only simple queries compared to MySQL, and doesn't support secondary indexes. Our HBase clusters store large tables that don't require complex range or aggregation queries. For example, we use HBase to store the cached feed contents for each user, or the mapping between shortened http://qr.ae URLs to the original URLs. In our environment, HBase is slower than MySQL — the p50 latency for our clusters is around 1ms and the p90 latency is around 10 ms.RedisIn addition to using Redis as a cache, we also use it as a ground-truth datastore. The ground-truth cluster is configured differently than the cache cluster - for example, there are replicas, backups are enabled, and eviction is disabled.Because each Redis process is single-threaded, we run multiple Redis processes on each EC2 instance to utilize all of the CPU cores. We use nutcracker to distribute traffic to each of the Redis processes running on all instances in the cluster. Because each Redis process is single-threaded, a slow query can still block other queries on the same shard. For our use cases, Redis commands with O(1) and O(log(N)) complexity are generally acceptable. We restrict our usage of commands with linear time (e.g ZRANGEBYSCORE) and forbid some commands entirely.Redis is much faster than MySQL or HBase; because all the data is stored in memory, no disk access is necessary. For our Redis cluster, the p90 latency is < 1ms. However, it also means that Redis is much more expensive than MySQL or HBase. We use ground-truth Redis to store only small amounts of data; for example, the last visit time for an user, or the status for our offline tasks.At Quora, a small team of only six people within our Infrastructure team operates all of these datastores and other critical online systems that power Quora. Follow the question What does the Infrastructure team do at Quora? to learn more about what we do. If any of this sounds interesting to you, consider joining us!

Can I sue my landlord? His friend posted my name and picture online claiming that I am holding over and haven't paid rent for a year (true). My landlord is having a eviction proceeding against me, can I use this as a defense to dismiss the case?For the United States:Can I sue my landlord?Sure can! This is the good old U S of A and anyone can sue anyone else for anything they feel like. You’ll lose and likely end up liable for court costs and attorney’s fees, but go ahead and embarrass yourself.Your landlord didn’t do it. You might have a shot if it was against the friend that posted the information, but you’ve admitted publicly that the information is true. What would you sue for, the fact that someone told the truth about you?His friend posted my name and picture online claiming that I am holding over and haven't paid rent for a year (true). My landlord is having a eviction proceeding against me, can I use this as a defense to dismiss the case?Sure, go for it, I’m sure the Judge needs a good laugh. It’s should work just as well as murdering your landlord and using the defense that the landlord’s friend’s stepfathers’ ex-wife posted messages that she thought you were violent.I hope your landlord is on Quora, finds your question (with its admission of a year of non-payment), and uses it against you in court.

I had a couple in their late 20’s which was straight up disgusting. Their apartment was a constant state of upheaval, and they specialized in perfecting the science of unkempt. There’s no sense in sanitizing the issue, they were gross.Not only were they generally terrible, their rent record was spotty then stopped altogether.The female (of this hetero relationship) expressed that she was “pregnant” and my routine requests for rent were “stressing her out and may cause her to lose the baby.”She threatened me legally for causing her some twisted form of harm, threatening to sue and take everything I own. I’ve heard that before, no problem. We have numerous wonderful tenants and terrific relationships, and I expect the wing nut from time to time. We are responsible operators and can weather the threats as they swim in.One day during her pregnancy /slash/ eviction underway, she brought me an ultrasound picture and told me that my behavior had caused her unborn child to have a birth defect. She had been collecting baby clothing and begging for donations from friends, stacking up all of the effects necessary for a child-to-be.I paid very close attention to what she told me, then looked up the rare disorder online. The same ultrasound picture appeared in an article from several years prior in an out-of-state newspaper.There was no pregnancy.They left the apartment stacked with a roll off dumpster load of biohazard garbage.They’ve both been in and out of jail since for various legal flotsam.I love the comment on one of these answers which asks “why do landlords on this site act as if tenants are beneath them?”Most of us don’t. I don’t. In fact I communicate the opposite to tenants, as I express clearly I work for them until they prove I shouldn’t. I want tenants to be comfortable, secure and safe.The stories themselves are so bizarre and putrid it is not condescending to simply tell the truth. Landlords are, unfortunately, in a position where they must regularly serve in the paternalistic roles of pastor, teacher, counselor, accountant, parent and sociologist.The fact landlords deal with treacherous people does not make us aloof in contrast, it makes us miserable in reality. Laws are generally not in our favor, as more tenants can be called to the ballot box on any given day than us.Some people are disgusting, manipulative, lying thieves. Others have all of the above characteristics with a sprinkle or flood of sociopath.And that’s just too bad.Even worse is the poor property owners in Seattle who apparently can’t ask for background criminal information (because political sympathy). Yikes.