## CS 591 K1: Data Stream Processing and Analytics Spring 2020 ## 4 /02: Elasticity policies and state migration Vasiliki (Vasia) Kalavri vkalavri@bu.edu Streaming applications are long-running • Workload

of the algorithm. ## Execution policies Most algorithms have overloads that accept execution policies. The standard library algorithms support several execution policies, and the library provides corresponding nth/max_element • Much more efficient than sort • Works for any sortable range - Supports execution policies, comparison functions, concepts/requirements • Hides confusing iterator pair Midpoint available

hashes that were created from private data in previous transactions. - Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides Hyperledger Fabric Model • Blockchain network • Identity. • Membership Service Provider (MSP) • Policies • Peers • Ledger • The Ordering Service • Smart Contracts and Chaincode • Fabric chaincode ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies - Prior to appending a block, a versioning check is performed to ensure that states

hashes that were created from private data in previous transactions. - Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides Hyperledger Fabric Model • Blockchain network • Identity. • Membership Service Provider (MSP) • Policies • Peers • Ledger • The Ordering Service • Smart Contracts and Chaincode • Fabric chaincode ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies - Prior to appending a block, a versioning check is performed to ensure that states

hashes that were created from private data in previous transactions. - Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides Hyperledger Fabric Model • Blockchain network • Identity. • Membership Service Provider (MSP) • Policies • Peers • Ledger • The Ordering Service • Smart Contracts and Chaincode • Fabric chaincode ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies - Prior to appending a block, a versioning check is performed to ensure that states

hashes that were created from private data in previous transactions. • Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies • Prior to appending a block, a versioning check is performed to ensure that states transaction is validated and committed • A channel’s ledger contains a configuration block defining policies, access control lists, and other pertinent information • Channels contain Membership Service Provider

hashes that were created from private data in previous transactions. • Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies • Prior to appending a block, a versioning check is performed to ensure that states transaction is validated and committed • A channel’s ledger contains a configuration block defining policies, access control lists, and other pertinent information • Channels contain Membership Service Provider

hashes that were created from private data in previous transactions. • Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies • Prior to appending a block, a versioning check is performed to ensure that states transaction is validated and committed • A channel’s ledger contains a configuration block defining policies, access control lists, and other pertinent information • Channels contain Membership Service Provider

hashes that were created from private data in previous transactions. - Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides • Introduction • Hyperledger Fabric Model • Blockchain network • Identity. • Membership • Policies • Peers • Smart Contracts and Chaincode • Ledger • The Ordering Service • Private data • Channel ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies - Prior to appending a block, a versioning check is performed to ensure that states

hashes that were created from private data in previous transactions. - Collection-level endorsement policies Private data collections can now optionally be defined with an endorsement policy that overrides Hyperledger Fabric Model • Blockchain network • Identity. • Membership Service Provider (MSP) • Policies • Peers • Ledger • The Ordering Service • Smart Contracts and Chaincode • Fabric chaincode ordering service to peers on a channel • Peers validate transactions against endorsement policies and enforce the policies - Prior to appending a block, a versioning check is performed to ensure that states