diff --git a/src/addrman.h b/src/addrman.h index 5d49b99a6..916f4da4b 100644 --- a/src/addrman.h +++ b/src/addrman.h @@ -98,49 +98,49 @@ public: }; -// Stochastic address manager -// -// Design goals: -// * Only keep a limited number of addresses around, so that addr.dat and memory requirements do not grow without bound. -// * Keep the address tables in-memory, and asynchronously dump the entire to able in addr.dat. -// * Make sure no (localized) attacker can fill the entire table with his nodes/addresses. -// -// To that end: -// * Addresses are organized into buckets. -// * Address that have not yet been tried go into 256 "new" buckets. -// * Based on the address range (/16 for IPv4) of source of the information, 32 buckets are selected at random -// * The actual bucket is chosen from one of these, based on the range the address itself is located. -// * One single address can occur in up to 4 different buckets, to increase selection chances for addresses that -// are seen frequently. The chance for increasing this multiplicity decreases exponentially. -// * When adding a new address to a full bucket, a randomly chosen entry (with a bias favoring less recently seen -// ones) is removed from it first. -// * Addresses of nodes that are known to be accessible go into 64 "tried" buckets. -// * Each address range selects at random 4 of these buckets. -// * The actual bucket is chosen from one of these, based on the full address. -// * When adding a new good address to a full bucket, a randomly chosen entry (with a bias favoring less recently -// tried ones) is evicted from it, back to the "new" buckets. -// * Bucket selection is based on cryptographic hashing, using a randomly-generated 256-bit key, which should not -// be observable by adversaries. -// * Several indexes are kept for high performance. Defining DEBUG_ADDRMAN will introduce frequent (and expensive) -// consistency checks for the entire data structure. +/** Stochastic address manager + * + * Design goals: + * * Keep the address tables in-memory, and asynchronously dump the entire to able in peers.dat. + * * Make sure no (localized) attacker can fill the entire table with his nodes/addresses. + * + * To that end: + * * Addresses are organized into buckets. + * * Address that have not yet been tried go into 1024 "new" buckets. + * * Based on the address range (/16 for IPv4) of source of the information, 64 buckets are selected at random + * * The actual bucket is chosen from one of these, based on the range the address itself is located. + * * One single address can occur in up to 8 different buckets, to increase selection chances for addresses that + * are seen frequently. The chance for increasing this multiplicity decreases exponentially. + * * When adding a new address to a full bucket, a randomly chosen entry (with a bias favoring less recently seen + * ones) is removed from it first. + * * Addresses of nodes that are known to be accessible go into 256 "tried" buckets. + * * Each address range selects at random 8 of these buckets. + * * The actual bucket is chosen from one of these, based on the full address. + * * When adding a new good address to a full bucket, a randomly chosen entry (with a bias favoring less recently + * tried ones) is evicted from it, back to the "new" buckets. + * * Bucket selection is based on cryptographic hashing, using a randomly-generated 256-bit key, which should not + * be observable by adversaries. + * * Several indexes are kept for high performance. Defining DEBUG_ADDRMAN will introduce frequent (and expensive) + * consistency checks for the entire data structure. + */ // total number of buckets for tried addresses -#define ADDRMAN_TRIED_BUCKET_COUNT 64 +#define ADDRMAN_TRIED_BUCKET_COUNT 256 // total number of buckets for new addresses -#define ADDRMAN_NEW_BUCKET_COUNT 256 +#define ADDRMAN_NEW_BUCKET_COUNT 1024 // maximum allowed number of entries in buckets for new and tried addresses #define ADDRMAN_BUCKET_SIZE 64 // over how many buckets entries with tried addresses from a single group (/16 for IPv4) are spread -#define ADDRMAN_TRIED_BUCKETS_PER_GROUP 4 +#define ADDRMAN_TRIED_BUCKETS_PER_GROUP 8 // over how many buckets entries with new addresses originating from a single group are spread -#define ADDRMAN_NEW_BUCKETS_PER_SOURCE_GROUP 32 +#define ADDRMAN_NEW_BUCKETS_PER_SOURCE_GROUP 64 // in how many buckets for entries with new addresses a single address may occur -#define ADDRMAN_NEW_BUCKETS_PER_ADDRESS 4 +#define ADDRMAN_NEW_BUCKETS_PER_ADDRESS 8 // how old addresses can maximally be #define ADDRMAN_HORIZON_DAYS 30