offset, a monotonically increasing sequence number • Within a partition, all messages are totally ordered but there is no ordering guarantee across partitions 28 29 Failure handling • The broker

Kalavri | Boston University 2020 Operator types (II) • Sequence Operators capture the arrival of an ordered set of events. • common in pattern languages • events must have associated timestamps • Iteration 2020 Model and formalization (I) A stream is a sequence of unbounded length, where tuples are ordered by their arrival time. Sequence: Let t1, … ,tn be tuples from a relation R. The list S = [t1, Kalavri | Boston University 2020 Timestamped streams Pre-sequence: Let S and R be two sequences ordered by their timestamp and Rτ be the set of tuples of R with timestamp less than or equal to τ > 0.

written to it. For each topic, the Kafka cluster maintains a partitioned log. Each partition is an ordered, immutable sequence of records that is continually appended to—a structured commit log. An offset

serialization and deserialization is required to access the state via a Flink program. • The keys are ordered according to a user-specified comparator function. Basic operations • Get(key): fetch a single

Shedding Road Map (LSRM) • A pre-computed table that contains materialized load shedding plans ordered by how much load shedding they will cause. • Each row contains a plan with • expected cycle

inserted to the filter, what is the probability P0 that a bit is still 0? 1. The probability that h1 sets bit j is 1 n 1 0 1 1 1 0 0 1 1 1 1 0 1 1 n bits h1 h2 hk … k hash functions 1 0 ??? Vasiliki inserted to the filter, what is the probability P0 that a bit is still 0? 1. The probability that h1 sets bit j is 1 n 2. The probability that a bit was not set by any of the k hash functions is (1 − inserted to the filter, what is the probability P0 that a bit is still 0? 1. The probability that h1 sets bit j is 1 n 2. The probability that a bit was not set by any of the k hash functions is (1 −

source Id 2. maintain a disjoint set in each partition 3. periodically merge the partial disjoint sets into a global one ??? Vasiliki Kalavri | Boston University 2020 Connected components in Flink University 2020 A graph is bipartite if its vertex set can be divided into two disjoint independent sets U, V, such that every edge connects a vertex in U to a vertex in V (no edges between vertices in

states over a common schema R: [r1(R), r2(R), ..., ], where the individual relations are unordered sets. src dest bytes 1 2 20K 2 5 32K 1 2 28K {(1, 2, 20K), (2, 5, 32K), (1, 2, 28K)} 25 Vasiliki